pugixml.cpp

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/**
 * pugixml parser - version 1.8
 * --------------------------------------------------------
 * Copyright (C) 2006-2016, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
 * Report bugs and download new versions at http://pugixml.org/
 *
 * This library is distributed under the MIT License. See notice at the end
 * of this file.
 *
 * This work is based on the pugxml parser, which is:
 * Copyright (C) 2003, by Kristen Wegner (kristen@tima.net)
 */
// clang-format off

#ifndef SOURCE_PUGIXML_CPP
#define SOURCE_PUGIXML_CPP

#include "pugixml.hpp"

#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cassert>
#include <climits>

#ifdef PUGIXML_WCHAR_MODE
#       include <wchar.h>
#endif

#ifndef PUGIXML_NO_XPATH
#       include <cmath>
#       include <cfloat>
#       ifdef PUGIXML_NO_EXCEPTIONS
#               include <setjmp.h>
#       endif
#endif

#ifndef PUGIXML_NO_STL
#       include <istream>
#       include <ostream>
#       include <string>
#endif

// For placement new
#include <new>

#ifdef _MSC_VER
#       pragma warning(push)
#       pragma warning(disable: 4127) // conditional expression is constant
#       pragma warning(disable: 4324) // structure was padded due to __declspec(align())
#       pragma warning(disable: 4611) // interaction between '_setjmp' and C++ object destruction is non-portable
#       pragma warning(disable: 4702) // unreachable code
#       pragma warning(disable: 4996) // this function or variable may be unsafe
#       pragma warning(disable: 4793) // function compiled as native: presence of '_setjmp' makes a function unmanaged
#endif

#ifdef __INTEL_COMPILER
#       pragma warning(disable: 177) // function was declared but never referenced
#       pragma warning(disable: 279) // controlling expression is constant
#       pragma warning(disable: 1478 1786) // function was declared "deprecated"
#       pragma warning(disable: 1684) // conversion from pointer to same-sized integral type
#endif

#if defined(__BORLANDC__) && defined(PUGIXML_HEADER_ONLY)
#       pragma warn -8080 // symbol is declared but never used; disabling this inside push/pop bracket does not make the warning go away
#endif

#ifdef __BORLANDC__
#       pragma option push
#       pragma warn -8008 // condition is always false
#       pragma warn -8066 // unreachable code
#endif

#ifdef __SNC__
// Using diag_push/diag_pop does not disable the warnings inside templates due to a compiler bug
#       pragma diag_suppress=178 // function was declared but never referenced
#       pragma diag_suppress=237 // controlling expression is constant
#endif

// Inlining controls
#if defined(_MSC_VER) && _MSC_VER >= 1300
#       define PUGI__NO_INLINE __declspec(noinline)
#elif defined(__GNUC__)
#       define PUGI__NO_INLINE __attribute__((noinline))
#else
#       define PUGI__NO_INLINE
#endif

// Branch weight controls
#if defined(__GNUC__)
#       define PUGI__UNLIKELY(cond) __builtin_expect(cond, 0)
#else
#       define PUGI__UNLIKELY(cond) (cond)
#endif

// Simple static assertion
#define PUGI__STATIC_ASSERT(cond) { static const char condition_failed[(cond) ? 1 : -1] = {0}; (void)condition_failed[0]; }

// Digital Mars C++ bug workaround for passing char loaded from memory via stack
#ifdef __DMC__
#       define PUGI__DMC_VOLATILE volatile
#else
#       define PUGI__DMC_VOLATILE
#endif

// Borland C++ bug workaround for not defining ::memcpy depending on header include order (can't always use std::memcpy because some compilers don't have it at all)
#if defined(__BORLANDC__) && !defined(__MEM_H_USING_LIST)
using std::memcpy;
using std::memmove;
using std::memset;
#endif

// Some MinGW versions have headers that erroneously omit LLONG_MIN/LLONG_MAX/ULLONG_MAX definitions in strict ANSI mode
#if defined(PUGIXML_HAS_LONG_LONG) && defined(__MINGW32__) && defined(__STRICT_ANSI__) && !defined(LLONG_MAX) && !defined(LLONG_MIN) && !defined(ULLONG_MAX)
#       define LLONG_MAX 9223372036854775807LL
#       define LLONG_MIN (-LLONG_MAX-1)
#       define ULLONG_MAX (2ULL*LLONG_MAX+1)
#endif

// In some environments MSVC is a compiler but the CRT lacks certain MSVC-specific features
#if defined(_MSC_VER) && !defined(__S3E__)
#       define PUGI__MSVC_CRT_VERSION _MSC_VER
#endif

#ifdef PUGIXML_HEADER_ONLY
#       define PUGI__NS_BEGIN OIIO_NAMESPACE_BEGIN namespace pugi { namespace impl {
#       define PUGI__NS_END } } OIIO_NAMESPACE_END
#       define PUGI__FN inline
#       define PUGI__FN_NO_INLINE inline
#else
#       if defined(_MSC_VER) && _MSC_VER < 1300 // MSVC6 seems to have an amusing bug with anonymous namespaces inside namespaces
#               define PUGI__NS_BEGIN OIIO_NAMESPACE_BEGIN namespace pugi { namespace impl {
#               define PUGI__NS_END } } OIIO_NAMESPACE_END
#       else
#               define PUGI__NS_BEGIN OIIO_NAMESPACE_BEGIN namespace pugi { namespace impl { namespace {
#               define PUGI__NS_END } } } OIIO_NAMESPACE_END
#       endif
#       define PUGI__FN
#       define PUGI__FN_NO_INLINE PUGI__NO_INLINE
#endif

// uintptr_t
#if (defined(_MSC_VER) && _MSC_VER < 1600) || (defined(__BORLANDC__) && __BORLANDC__ < 0x561)
OIIO_NAMESPACE_BEGIN namespace pugi
{
#       ifndef _UINTPTR_T_DEFINED
        typedef size_t uintptr_t;
#       endif

        typedef unsigned __int8 uint8_t;
        typedef unsigned __int16 uint16_t;
        typedef unsigned __int32 uint32_t;
} OIIO_NAMESPACE_END
#else
#       include <cstdint>
#endif

// Memory allocation
PUGI__NS_BEGIN
        PUGI__FN void* default_allocate(size_t size)
        {
                return malloc(size);
        }

        PUGI__FN void default_deallocate(void* ptr)
        {
                free(ptr);
        }

        template <typename T>
        struct xml_memory_management_function_storage
        {
                static allocation_function allocate;
                static deallocation_function deallocate;
        };

        // Global allocation functions are stored in class statics so that in header mode linker deduplicates them
        // Without a template<> we'll get multiple definitions of the same static
        template <typename T> allocation_function xml_memory_management_function_storage<T>::allocate = default_allocate;
        template <typename T> deallocation_function xml_memory_management_function_storage<T>::deallocate = default_deallocate;

        typedef xml_memory_management_function_storage<int> xml_memory;
PUGI__NS_END

// String utilities
PUGI__NS_BEGIN
        // Get string length
        PUGI__FN size_t strlength(const char_t* s)
        {
                assert(s);

        #ifdef PUGIXML_WCHAR_MODE
                return wcslen(s);
        #else
                return strlen(s);
        #endif
        }

        // Compare two strings
        PUGI__FN bool strequal(const char_t* src, const char_t* dst)
        {
                assert(src && dst);

        #ifdef PUGIXML_WCHAR_MODE
                return wcscmp(src, dst) == 0;
        #else
                return strcmp(src, dst) == 0;
        #endif
        }

        // Compare lhs with [rhs_begin, rhs_end)
        PUGI__FN bool strequalrange(const char_t* lhs, const char_t* rhs, size_t count)
        {
                for (size_t i = 0; i < count; ++i)
                        if (lhs[i] != rhs[i])
                                return false;

                return lhs[count] == 0;
        }

        // Get length of wide string, even if CRT lacks wide character support
        PUGI__FN size_t strlength_wide(const wchar_t* s)
        {
                assert(s);

        #ifdef PUGIXML_WCHAR_MODE
                return wcslen(s);
        #else
                const wchar_t* end = s;
                while (*end) end++;
                return static_cast<size_t>(end - s);
        #endif
        }
PUGI__NS_END

// auto_ptr-like object for exception recovery
PUGI__NS_BEGIN
        template <typename T> struct auto_deleter
        {
                typedef void (*D)(T*);

                T* data;
                D deleter;

                auto_deleter(T* data_, D deleter_): data(data_), deleter(deleter_)
                {
                }

                ~auto_deleter()
                {
                        if (data) deleter(data);
                }

                T* release()
                {
                        T* result = data;
                        data = 0;
                        return result;
                }
        };
PUGI__NS_END

#ifdef PUGIXML_COMPACT
PUGI__NS_BEGIN
        class compact_hash_table
        {
        public:
                compact_hash_table(): _items(0), _capacity(0), _count(0)
                {
                }

                void clear()
                {
                        if (_items)
                        {
                                xml_memory::deallocate(_items);
                                _items = 0;
                                _capacity = 0;
                                _count = 0;
                        }
                }

                void** find(const void* key)
                {
                        assert(key);

                        if (_capacity == 0) return 0;

                        size_t hashmod = _capacity - 1;
                        size_t bucket = hash(key) & hashmod;

                        for (size_t probe = 0; probe <= hashmod; ++probe)
                        {
                                item_t& probe_item = _items[bucket];

                                if (probe_item.key == key)
                                        return &probe_item.value;

                                if (probe_item.key == 0)
                                        return 0;

                                // hash collision, quadratic probing
                                bucket = (bucket + probe + 1) & hashmod;
                        }

                        assert(false && "Hash table is full");
                        return 0;
                }

                void** insert(const void* key)
                {
                        assert(key);
                        assert(_capacity != 0 && _count < _capacity - _capacity / 4);

                        size_t hashmod = _capacity - 1;
                        size_t bucket = hash(key) & hashmod;

                        for (size_t probe = 0; probe <= hashmod; ++probe)
                        {
                                item_t& probe_item = _items[bucket];

                                if (probe_item.key == 0)
                                {
                                        probe_item.key = key;
                                        _count++;
                                        return &probe_item.value;
                                }

                                if (probe_item.key == key)
                                        return &probe_item.value;

                                // hash collision, quadratic probing
                                bucket = (bucket + probe + 1) & hashmod;
                        }

                        assert(false && "Hash table is full");
                        return 0;
                }

                bool reserve()
                {
                        if (_count + 16 >= _capacity - _capacity / 4)
                                return rehash();

                        return true;
                }

        private:
                struct item_t
                {
                        const void* key;
                        void* value;
                };

                item_t* _items;
                size_t _capacity;

                size_t _count;

                bool rehash();

                static unsigned int hash(const void* key)
                {
                        unsigned int h = static_cast<unsigned int>(reinterpret_cast<uintptr_t>(key));

                        // MurmurHash3 32-bit finalizer
                        h ^= h >> 16;
                        h *= 0x85ebca6bu;
                        h ^= h >> 13;
                        h *= 0xc2b2ae35u;
                        h ^= h >> 16;

                        return h;
                }
        };

        PUGI__FN_NO_INLINE bool compact_hash_table::rehash()
        {
                compact_hash_table rt;
                rt._capacity = (_capacity == 0) ? 32 : _capacity * 2;
                rt._items = static_cast<item_t*>(xml_memory::allocate(sizeof(item_t) * rt._capacity));

                if (!rt._items)
                        return false;

                memset(rt._items, 0, sizeof(item_t) * rt._capacity);

                for (size_t i = 0; i < _capacity; ++i)
                        if (_items[i].key)
                                *rt.insert(_items[i].key) = _items[i].value;

                if (_items)
                        xml_memory::deallocate(_items);

                _capacity = rt._capacity;
                _items = rt._items;

                assert(_count == rt._count);

                return true;
        }

PUGI__NS_END
#endif

PUGI__NS_BEGIN
#ifdef PUGIXML_COMPACT
        static const uintptr_t xml_memory_block_alignment = 4;
#else
        static const uintptr_t xml_memory_block_alignment = sizeof(void*);
#endif

        // extra metadata bits
        static const uintptr_t xml_memory_page_contents_shared_mask = 64;
        static const uintptr_t xml_memory_page_name_allocated_mask = 32;
        static const uintptr_t xml_memory_page_value_allocated_mask = 16;
        static const uintptr_t xml_memory_page_type_mask = 15;

        // combined masks for string uniqueness
        static const uintptr_t xml_memory_page_name_allocated_or_shared_mask = xml_memory_page_name_allocated_mask | xml_memory_page_contents_shared_mask;
        static const uintptr_t xml_memory_page_value_allocated_or_shared_mask = xml_memory_page_value_allocated_mask | xml_memory_page_contents_shared_mask;

#ifdef PUGIXML_COMPACT
        #define PUGI__GETHEADER_IMPL(object, page, flags) // unused
        #define PUGI__GETPAGE_IMPL(header) (header).get_page()
#else
        #define PUGI__GETHEADER_IMPL(object, page, flags) (((reinterpret_cast<char*>(object) - reinterpret_cast<char*>(page)) << 8) | (flags))
        // this macro casts pointers through void* to avoid 'cast increases required alignment of target type' warnings
        #define PUGI__GETPAGE_IMPL(header) static_cast<impl::xml_memory_page*>(const_cast<void*>(static_cast<const void*>(reinterpret_cast<const char*>(&header) - (header >> 8))))
#endif

        #define PUGI__GETPAGE(n) PUGI__GETPAGE_IMPL((n)->header)
        #define PUGI__NODETYPE(n) static_cast<xml_node_type>((n)->header & impl::xml_memory_page_type_mask)

        struct xml_allocator;

        struct xml_memory_page
        {
                static xml_memory_page* construct(void* memory)
                {
                        xml_memory_page* result = static_cast<xml_memory_page*>(memory);

                        result->allocator = 0;
                        result->prev = 0;
                        result->next = 0;
                        result->busy_size = 0;
                        result->freed_size = 0;

                #ifdef PUGIXML_COMPACT
                        result->compact_string_base = 0;
                        result->compact_shared_parent = 0;
                        result->compact_page_marker = 0;
                #endif

                        return result;
                }

                xml_allocator* allocator;

                xml_memory_page* prev;
                xml_memory_page* next;

                size_t busy_size;
                size_t freed_size;

        #ifdef PUGIXML_COMPACT
                char_t* compact_string_base;
                void* compact_shared_parent;
                uint32_t* compact_page_marker;
        #endif
        };

        static const size_t xml_memory_page_size =
        #ifdef PUGIXML_MEMORY_PAGE_SIZE
                (PUGIXML_MEMORY_PAGE_SIZE)
        #else
                32768
        #endif
                - sizeof(xml_memory_page);

        struct xml_memory_string_header
        {
                uint16_t page_offset; // offset from page->data
                uint16_t full_size; // 0 if string occupies whole page
        };

        struct xml_allocator
        {
                xml_allocator(xml_memory_page* root): _root(root), _busy_size(root->busy_size)
                {
                #ifdef PUGIXML_COMPACT
                        _hash = 0;
                #endif
                }

                xml_memory_page* allocate_page(size_t data_size)
                {
                        size_t size = sizeof(xml_memory_page) + data_size;

                        // allocate block with some alignment, leaving memory for worst-case padding
                        void* memory = xml_memory::allocate(size);
                        if (!memory) return 0;

                        // prepare page structure
                        xml_memory_page* page = xml_memory_page::construct(memory);
                        assert(page);

                        page->allocator = _root->allocator;

                        return page;
                }

                static void deallocate_page(xml_memory_page* page)
                {
                        xml_memory::deallocate(page);
                }

                void* allocate_memory_oob(size_t size, xml_memory_page*& out_page);

                void* allocate_memory(size_t size, xml_memory_page*& out_page)
                {
                        if (PUGI__UNLIKELY(_busy_size + size > xml_memory_page_size))
                                return allocate_memory_oob(size, out_page);

                        void* buf = reinterpret_cast<char*>(_root) + sizeof(xml_memory_page) + _busy_size;

                        _busy_size += size;

                        out_page = _root;

                        return buf;
                }

        #ifdef PUGIXML_COMPACT
                void* allocate_object(size_t size, xml_memory_page*& out_page)
                {
                        void* result = allocate_memory(size + sizeof(uint32_t), out_page);
                        if (!result) return 0;

                        // adjust for marker
                        ptrdiff_t offset = static_cast<char*>(result) - reinterpret_cast<char*>(out_page->compact_page_marker);

                        if (PUGI__UNLIKELY(static_cast<uintptr_t>(offset) >= 256 * xml_memory_block_alignment))
                        {
                                // insert new marker
                                uint32_t* marker = static_cast<uint32_t*>(result);

                                *marker = static_cast<uint32_t>(reinterpret_cast<char*>(marker) - reinterpret_cast<char*>(out_page));
                                out_page->compact_page_marker = marker;

                                // since we don't reuse the page space until we reallocate it, we can just pretend that we freed the marker block
                                // this will make sure deallocate_memory correctly tracks the size
                                out_page->freed_size += sizeof(uint32_t);

                                return marker + 1;
                        }
                        else
                        {
                                // roll back uint32_t part
                                _busy_size -= sizeof(uint32_t);

                                return result;
                        }
                }
        #else
                void* allocate_object(size_t size, xml_memory_page*& out_page)
                {
                        return allocate_memory(size, out_page);
                }
        #endif

                void deallocate_memory(void* ptr, size_t size, xml_memory_page* page)
                {
                        if (page == _root) page->busy_size = _busy_size;

                        assert(ptr >= reinterpret_cast<char*>(page) + sizeof(xml_memory_page) && ptr < reinterpret_cast<char*>(page) + sizeof(xml_memory_page) + page->busy_size);
                        (void)!ptr;

                        page->freed_size += size;
                        assert(page->freed_size <= page->busy_size);

                        if (page->freed_size == page->busy_size)
                        {
                                if (page->next == 0)
                                {
                                        assert(_root == page);

                                        // top page freed, just reset sizes
                                        page->busy_size = 0;
                                        page->freed_size = 0;

                                #ifdef PUGIXML_COMPACT
                                        // reset compact state to maximize efficiency
                                        page->compact_string_base = 0;
                                        page->compact_shared_parent = 0;
                                        page->compact_page_marker = 0;
                                #endif

                                        _busy_size = 0;
                                }
                                else
                                {
                                        assert(_root != page);
                                        assert(page->prev);

                                        // remove from the list
                                        page->prev->next = page->next;
                                        page->next->prev = page->prev;

                                        // deallocate
                                        deallocate_page(page);
                                }
                        }
                }

                char_t* allocate_string(size_t length)
                {
                        static const size_t max_encoded_offset = (1 << 16) * xml_memory_block_alignment;

                        PUGI__STATIC_ASSERT(xml_memory_page_size <= max_encoded_offset);

                        // allocate memory for string and header block
                        size_t size = sizeof(xml_memory_string_header) + length * sizeof(char_t);

                        // round size up to block alignment boundary
                        size_t full_size = (size + (xml_memory_block_alignment - 1)) & ~(xml_memory_block_alignment - 1);

                        xml_memory_page* page;
                        xml_memory_string_header* header = static_cast<xml_memory_string_header*>(allocate_memory(full_size, page));

                        if (!header) return 0;

                        // setup header
                        ptrdiff_t page_offset = reinterpret_cast<char*>(header) - reinterpret_cast<char*>(page) - sizeof(xml_memory_page);

                        assert(page_offset % xml_memory_block_alignment == 0);
                        assert(page_offset >= 0 && static_cast<size_t>(page_offset) < max_encoded_offset);
                        header->page_offset = static_cast<uint16_t>(static_cast<size_t>(page_offset) / xml_memory_block_alignment);

                        // full_size == 0 for large strings that occupy the whole page
                        assert(full_size % xml_memory_block_alignment == 0);
                        assert(full_size < max_encoded_offset || (page->busy_size == full_size && page_offset == 0));
                        header->full_size = static_cast<uint16_t>(full_size < max_encoded_offset ? full_size / xml_memory_block_alignment : 0);

                        // round-trip through void* to avoid 'cast increases required alignment of target type' warning
                        // header is guaranteed a pointer-sized alignment, which should be enough for char_t
                        return static_cast<char_t*>(static_cast<void*>(header + 1));
                }

                void deallocate_string(char_t* string)
                {
                        // this function casts pointers through void* to avoid 'cast increases required alignment of target type' warnings
                        // we're guaranteed the proper (pointer-sized) alignment on the input string if it was allocated via allocate_string

                        // get header
                        xml_memory_string_header* header = static_cast<xml_memory_string_header*>(static_cast<void*>(string)) - 1;
                        assert(header);

                        // deallocate
                        size_t page_offset = sizeof(xml_memory_page) + header->page_offset * xml_memory_block_alignment;
                        xml_memory_page* page = reinterpret_cast<xml_memory_page*>(static_cast<void*>(reinterpret_cast<char*>(header) - page_offset));

                        // if full_size == 0 then this string occupies the whole page
                        size_t full_size = header->full_size == 0 ? page->busy_size : header->full_size * xml_memory_block_alignment;

                        deallocate_memory(header, full_size, page);
                }

                bool reserve()
                {
                #ifdef PUGIXML_COMPACT
                        return _hash->reserve();
                #else
                        return true;
                #endif
                }

                xml_memory_page* _root;
                size_t _busy_size;

        #ifdef PUGIXML_COMPACT
                compact_hash_table* _hash;
        #endif
        };

        PUGI__FN_NO_INLINE void* xml_allocator::allocate_memory_oob(size_t size, xml_memory_page*& out_page)
        {
                const size_t large_allocation_threshold = xml_memory_page_size / 4;

                xml_memory_page* page = allocate_page(size <= large_allocation_threshold ? xml_memory_page_size : size);
                out_page = page;

                if (!page) return 0;

                if (size <= large_allocation_threshold)
                {
                        _root->busy_size = _busy_size;

                        // insert page at the end of linked list
                        page->prev = _root;
                        _root->next = page;
                        _root = page;

                        _busy_size = size;
                }
                else
                {
                        // insert page before the end of linked list, so that it is deleted as soon as possible
                        // the last page is not deleted even if it's empty (see deallocate_memory)
                        assert(_root->prev);

                        page->prev = _root->prev;
                        page->next = _root;

                        _root->prev->next = page;
                        _root->prev = page;

                        page->busy_size = size;
                }

                return reinterpret_cast<char*>(page) + sizeof(xml_memory_page);
        }
PUGI__NS_END

#ifdef PUGIXML_COMPACT
PUGI__NS_BEGIN
        static const uintptr_t compact_alignment_log2 = 2;
        static const uintptr_t compact_alignment = 1 << compact_alignment_log2;

        class compact_header
        {
        public:
                compact_header(xml_memory_page* page, unsigned int flags)
                {
                        PUGI__STATIC_ASSERT(xml_memory_block_alignment == compact_alignment);

                        ptrdiff_t offset = (reinterpret_cast<char*>(this) - reinterpret_cast<char*>(page->compact_page_marker));
                        assert(offset % compact_alignment == 0 && static_cast<uintptr_t>(offset) < 256 * compact_alignment);

                        _page = static_cast<unsigned char>(offset >> compact_alignment_log2);
                        _flags = static_cast<unsigned char>(flags);
                }

                void operator&=(uintptr_t mod)
                {
                        _flags &= static_cast<unsigned char>(mod);
                }

                void operator|=(uintptr_t mod)
                {
                        _flags |= static_cast<unsigned char>(mod);
                }

                uintptr_t operator&(uintptr_t mod) const
                {
                        return _flags & mod;
                }

                xml_memory_page* get_page() const
                {
                        // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                        const char* page_marker = reinterpret_cast<const char*>(this) - (_page << compact_alignment_log2);
                        const char* page = page_marker - *reinterpret_cast<const uint32_t*>(static_cast<const void*>(page_marker));

                        return const_cast<xml_memory_page*>(reinterpret_cast<const xml_memory_page*>(static_cast<const void*>(page)));
                }

        private:
                unsigned char _page;
                unsigned char _flags;
        };

        PUGI__FN xml_memory_page* compact_get_page(const void* object, int header_offset)
        {
                const compact_header* header = reinterpret_cast<const compact_header*>(static_cast<const char*>(object) - header_offset);

                return header->get_page();
        }

        template <int header_offset, typename T> PUGI__FN_NO_INLINE T* compact_get_value(const void* object)
        {
                return static_cast<T*>(*compact_get_page(object, header_offset)->allocator->_hash->find(object));
        }

        template <int header_offset, typename T> PUGI__FN_NO_INLINE void compact_set_value(const void* object, T* value)
        {
                *compact_get_page(object, header_offset)->allocator->_hash->insert(object) = value;
        }

        template <typename T, int header_offset, int start = -126> class compact_pointer
        {
        public:
                compact_pointer(): _data(0)
                {
                }

                void operator=(const compact_pointer& rhs)
                {
                        *this = rhs + 0;
                }

                void operator=(T* value)
                {
                        if (value)
                        {
                                // value is guaranteed to be compact-aligned; 'this' is not
                                // our decoding is based on 'this' aligned to compact alignment downwards (see operator T*)
                                // so for negative offsets (e.g. -3) we need to adjust the diff by compact_alignment - 1 to
                                // compensate for arithmetic shift rounding for negative values
                                ptrdiff_t diff = reinterpret_cast<char*>(value) - reinterpret_cast<char*>(this);
                                ptrdiff_t offset = ((diff + int(compact_alignment - 1)) >> compact_alignment_log2) - start;

                                if (static_cast<uintptr_t>(offset) <= 253)
                                        _data = static_cast<unsigned char>(offset + 1);
                                else
                                {
                                        compact_set_value<header_offset>(this, value);

                                        _data = 255;
                                }
                        }
                        else
                                _data = 0;
                }

                operator T*() const
                {
                        if (_data)
                        {
                                if (_data < 255)
                                {
                                        uintptr_t base = reinterpret_cast<uintptr_t>(this) & ~(compact_alignment - 1);

                                        return reinterpret_cast<T*>(base + ((_data - 1 + start) << compact_alignment_log2));
                                }
                                else
                                        return compact_get_value<header_offset, T>(this);
                        }
                        else
                                return 0;
                }

                T* operator->() const
                {
                        return *this;
                }

        private:
                unsigned char _data;
        };

        template <typename T, int header_offset> class compact_pointer_parent
        {
        public:
                compact_pointer_parent(): _data(0)
                {
                }

                void operator=(const compact_pointer_parent& rhs)
                {
                        *this = rhs + 0;
                }

                void operator=(T* value)
                {
                        if (value)
                        {
                                // value is guaranteed to be compact-aligned; 'this' is not
                                // our decoding is based on 'this' aligned to compact alignment downwards (see operator T*)
                                // so for negative offsets (e.g. -3) we need to adjust the diff by compact_alignment - 1 to
                                // compensate for arithmetic shift behavior for negative values
                                ptrdiff_t diff = reinterpret_cast<char*>(value) - reinterpret_cast<char*>(this);
                                ptrdiff_t offset = ((diff + int(compact_alignment - 1)) >> compact_alignment_log2) + 65533;

                                if (static_cast<uintptr_t>(offset) <= 65533)
                                {
                                        _data = static_cast<unsigned short>(offset + 1);
                                }
                                else
                                {
                                        xml_memory_page* page = compact_get_page(this, header_offset);

                                        if (PUGI__UNLIKELY(page->compact_shared_parent == 0))
                                                page->compact_shared_parent = value;

                                        if (page->compact_shared_parent == value)
                                        {
                                                _data = 65534;
                                        }
                                        else
                                        {
                                                compact_set_value<header_offset>(this, value);

                                                _data = 65535;
                                        }
                                }
                        }
                        else
                        {
                                _data = 0;
                        }
                }

                operator T*() const
                {
                        if (_data)
                        {
                                if (_data < 65534)
                                {
                                        uintptr_t base = reinterpret_cast<uintptr_t>(this) & ~(compact_alignment - 1);

                                        return reinterpret_cast<T*>(base + ((_data - 1 - 65533) << compact_alignment_log2));
                                }
                                else if (_data == 65534)
                                        return static_cast<T*>(compact_get_page(this, header_offset)->compact_shared_parent);
                                else
                                        return compact_get_value<header_offset, T>(this);
                        }
                        else
                                return 0;
                }

                T* operator->() const
                {
                        return *this;
                }

        private:
                uint16_t _data;
        };

        template <int header_offset, int base_offset> class compact_string
        {
        public:
                compact_string(): _data(0)
                {
                }

                void operator=(const compact_string& rhs)
                {
                        *this = rhs + 0;
                }

                void operator=(char_t* value)
                {
                        if (value)
                        {
                                xml_memory_page* page = compact_get_page(this, header_offset);

                                if (PUGI__UNLIKELY(page->compact_string_base == 0))
                                        page->compact_string_base = value;

                                ptrdiff_t offset = value - page->compact_string_base;

                                if (static_cast<uintptr_t>(offset) < (65535 << 7))
                                {
                                        // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                                        uint16_t* base = reinterpret_cast<uint16_t*>(static_cast<void*>(reinterpret_cast<char*>(this) - base_offset));

                                        if (*base == 0)
                                        {
                                                *base = static_cast<uint16_t>((offset >> 7) + 1);
                                                _data = static_cast<unsigned char>((offset & 127) + 1);
                                        }
                                        else
                                        {
                                                ptrdiff_t remainder = offset - ((*base - 1) << 7);

                                                if (static_cast<uintptr_t>(remainder) <= 253)
                                                {
                                                        _data = static_cast<unsigned char>(remainder + 1);
                                                }
                                                else
                                                {
                                                        compact_set_value<header_offset>(this, value);

                                                        _data = 255;
                                                }
                                        }
                                }
                                else
                                {
                                        compact_set_value<header_offset>(this, value);

                                        _data = 255;
                                }
                        }
                        else
                        {
                                _data = 0;
                        }
                }

                operator char_t*() const
                {
                        if (_data)
                        {
                                if (_data < 255)
                                {
                                        xml_memory_page* page = compact_get_page(this, header_offset);

                                        // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                                        const uint16_t* base = reinterpret_cast<const uint16_t*>(static_cast<const void*>(reinterpret_cast<const char*>(this) - base_offset));
                                        assert(*base);

                                        ptrdiff_t offset = ((*base - 1) << 7) + (_data - 1);

                                        return page->compact_string_base + offset;
                                }
                                else
                                {
                                        return compact_get_value<header_offset, char_t>(this);
                                }
                        }
                        else
                                return 0;
                }

        private:
                unsigned char _data;
        };
PUGI__NS_END
#endif

#ifdef PUGIXML_COMPACT
OIIO_NAMESPACE_BEGIN namespace pugi
{
        struct xml_attribute_struct
        {
                xml_attribute_struct(impl::xml_memory_page* page): header(page, 0), namevalue_base(0)
                {
                        PUGI__STATIC_ASSERT(sizeof(xml_attribute_struct) == 8);
                }

                impl::compact_header header;

                uint16_t namevalue_base;

                impl::compact_string<4, 2> name;
                impl::compact_string<5, 3> value;

                impl::compact_pointer<xml_attribute_struct, 6> prev_attribute_c;
                impl::compact_pointer<xml_attribute_struct, 7, 0> next_attribute;
        };

        struct xml_node_struct
        {
                xml_node_struct(impl::xml_memory_page* page, xml_node_type type): header(page, type), namevalue_base(0)
                {
                        PUGI__STATIC_ASSERT(sizeof(xml_node_struct) == 12);
                }

                impl::compact_header header;

                uint16_t namevalue_base;

                impl::compact_string<4, 2> name;
                impl::compact_string<5, 3> value;

                impl::compact_pointer_parent<xml_node_struct, 6> parent;

                impl::compact_pointer<xml_node_struct, 8, 0> first_child;

                impl::compact_pointer<xml_node_struct,  9>    prev_sibling_c;
                impl::compact_pointer<xml_node_struct, 10, 0> next_sibling;

                impl::compact_pointer<xml_attribute_struct, 11, 0> first_attribute;
        };
} OIIO_NAMESPACE_END
#else
OIIO_NAMESPACE_BEGIN namespace pugi
{
        struct xml_attribute_struct
        {
                xml_attribute_struct(impl::xml_memory_page* page): name(0), value(0), prev_attribute_c(0), next_attribute(0)
                {
                        header = PUGI__GETHEADER_IMPL(this, page, 0);
                }

                uintptr_t header;

                char_t* name;
                char_t* value;

                xml_attribute_struct* prev_attribute_c;
                xml_attribute_struct* next_attribute;
        };

        struct xml_node_struct
        {
                xml_node_struct(impl::xml_memory_page* page, xml_node_type type): name(0), value(0), parent(0), first_child(0), prev_sibling_c(0), next_sibling(0), first_attribute(0)
                {
                        header = PUGI__GETHEADER_IMPL(this, page, type);
                }

                uintptr_t header;

                char_t* name;
                char_t* value;

                xml_node_struct* parent;

                xml_node_struct* first_child;

                xml_node_struct* prev_sibling_c;
                xml_node_struct* next_sibling;

                xml_attribute_struct* first_attribute;
        };
} OIIO_NAMESPACE_END
#endif

PUGI__NS_BEGIN
        struct xml_extra_buffer
        {
                char_t* buffer;
                xml_extra_buffer* next;
        };

        struct xml_document_struct: public xml_node_struct, public xml_allocator
        {
                xml_document_struct(xml_memory_page* page): xml_node_struct(page, node_document), xml_allocator(page), buffer(0), extra_buffers(0)
                {
                }

                const char_t* buffer;

                xml_extra_buffer* extra_buffers;

        #ifdef PUGIXML_COMPACT
                compact_hash_table hash;
        #endif
        };

        template <typename Object> inline xml_allocator& get_allocator(const Object* object)
        {
                assert(object);

                return *PUGI__GETPAGE(object)->allocator;
        }

        template <typename Object> inline xml_document_struct& get_document(const Object* object)
        {
                assert(object);

                return *static_cast<xml_document_struct*>(PUGI__GETPAGE(object)->allocator);
        }
PUGI__NS_END

// Low-level DOM operations
PUGI__NS_BEGIN
        inline xml_attribute_struct* allocate_attribute(xml_allocator& alloc)
        {
                xml_memory_page* page;
                void* memory = alloc.allocate_object(sizeof(xml_attribute_struct), page);
                if (!memory) return 0;

                return new (memory) xml_attribute_struct(page);
        }

        inline xml_node_struct* allocate_node(xml_allocator& alloc, xml_node_type type)
        {
                xml_memory_page* page;
                void* memory = alloc.allocate_object(sizeof(xml_node_struct), page);
                if (!memory) return 0;

                return new (memory) xml_node_struct(page, type);
        }

        inline void destroy_attribute(xml_attribute_struct* a, xml_allocator& alloc)
        {
                if (a->header & impl::xml_memory_page_name_allocated_mask)
                        alloc.deallocate_string(a->name);

                if (a->header & impl::xml_memory_page_value_allocated_mask)
                        alloc.deallocate_string(a->value);

                alloc.deallocate_memory(a, sizeof(xml_attribute_struct), PUGI__GETPAGE(a));
        }

        inline void destroy_node(xml_node_struct* n, xml_allocator& alloc)
        {
                if (n->header & impl::xml_memory_page_name_allocated_mask)
                        alloc.deallocate_string(n->name);

                if (n->header & impl::xml_memory_page_value_allocated_mask)
                        alloc.deallocate_string(n->value);

                for (xml_attribute_struct* attr = n->first_attribute; attr; )
                {
                        xml_attribute_struct* next = attr->next_attribute;

                        destroy_attribute(attr, alloc);

                        attr = next;
                }

                for (xml_node_struct* child = n->first_child; child; )
                {
                        xml_node_struct* next = child->next_sibling;

                        destroy_node(child, alloc);

                        child = next;
                }

                alloc.deallocate_memory(n, sizeof(xml_node_struct), PUGI__GETPAGE(n));
        }

        inline void append_node(xml_node_struct* child, xml_node_struct* node)
        {
                child->parent = node;

                xml_node_struct* head = node->first_child;

                if (head)
                {
                        xml_node_struct* tail = head->prev_sibling_c;

                        tail->next_sibling = child;
                        child->prev_sibling_c = tail;
                        head->prev_sibling_c = child;
                }
                else
                {
                        node->first_child = child;
                        child->prev_sibling_c = child;
                }
        }

        inline void prepend_node(xml_node_struct* child, xml_node_struct* node)
        {
                child->parent = node;

                xml_node_struct* head = node->first_child;

                if (head)
                {
                        child->prev_sibling_c = head->prev_sibling_c;
                        head->prev_sibling_c = child;
                }
                else
                        child->prev_sibling_c = child;

                child->next_sibling = head;
                node->first_child = child;
        }

        inline void insert_node_after(xml_node_struct* child, xml_node_struct* node)
        {
                xml_node_struct* parent = node->parent;

                child->parent = parent;

                if (node->next_sibling)
                        node->next_sibling->prev_sibling_c = child;
                else
                        parent->first_child->prev_sibling_c = child;

                child->next_sibling = node->next_sibling;
                child->prev_sibling_c = node;

                node->next_sibling = child;
        }

        inline void insert_node_before(xml_node_struct* child, xml_node_struct* node)
        {
                xml_node_struct* parent = node->parent;

                child->parent = parent;

                if (node->prev_sibling_c->next_sibling)
                        node->prev_sibling_c->next_sibling = child;
                else
                        parent->first_child = child;

                child->prev_sibling_c = node->prev_sibling_c;
                child->next_sibling = node;

                node->prev_sibling_c = child;
        }

        inline void remove_node(xml_node_struct* node)
        {
                xml_node_struct* parent = node->parent;

                if (node->next_sibling)
                        node->next_sibling->prev_sibling_c = node->prev_sibling_c;
                else
                        parent->first_child->prev_sibling_c = node->prev_sibling_c;

                if (node->prev_sibling_c->next_sibling)
                        node->prev_sibling_c->next_sibling = node->next_sibling;
                else
                        parent->first_child = node->next_sibling;

                node->parent = 0;
                node->prev_sibling_c = 0;
                node->next_sibling = 0;
        }

        inline void append_attribute(xml_attribute_struct* attr, xml_node_struct* node)
        {
                xml_attribute_struct* head = node->first_attribute;

                if (head)
                {
                        xml_attribute_struct* tail = head->prev_attribute_c;

                        tail->next_attribute = attr;
                        attr->prev_attribute_c = tail;
                        head->prev_attribute_c = attr;
                }
                else
                {
                        node->first_attribute = attr;
                        attr->prev_attribute_c = attr;
                }
        }

        inline void prepend_attribute(xml_attribute_struct* attr, xml_node_struct* node)
        {
                xml_attribute_struct* head = node->first_attribute;

                if (head)
                {
                        attr->prev_attribute_c = head->prev_attribute_c;
                        head->prev_attribute_c = attr;
                }
                else
                        attr->prev_attribute_c = attr;

                attr->next_attribute = head;
                node->first_attribute = attr;
        }

        inline void insert_attribute_after(xml_attribute_struct* attr, xml_attribute_struct* place, xml_node_struct* node)
        {
                if (place->next_attribute)
                        place->next_attribute->prev_attribute_c = attr;
                else
                        node->first_attribute->prev_attribute_c = attr;

                attr->next_attribute = place->next_attribute;
                attr->prev_attribute_c = place;
                place->next_attribute = attr;
        }

        inline void insert_attribute_before(xml_attribute_struct* attr, xml_attribute_struct* place, xml_node_struct* node)
        {
                if (place->prev_attribute_c->next_attribute)
                        place->prev_attribute_c->next_attribute = attr;
                else
                        node->first_attribute = attr;

                attr->prev_attribute_c = place->prev_attribute_c;
                attr->next_attribute = place;
                place->prev_attribute_c = attr;
        }

        inline void remove_attribute(xml_attribute_struct* attr, xml_node_struct* node)
        {
                if (attr->next_attribute)
                        attr->next_attribute->prev_attribute_c = attr->prev_attribute_c;
                else
                        node->first_attribute->prev_attribute_c = attr->prev_attribute_c;

                if (attr->prev_attribute_c->next_attribute)
                        attr->prev_attribute_c->next_attribute = attr->next_attribute;
                else
                        node->first_attribute = attr->next_attribute;

                attr->prev_attribute_c = 0;
                attr->next_attribute = 0;
        }

        PUGI__FN_NO_INLINE xml_node_struct* append_new_node(xml_node_struct* node, xml_allocator& alloc, xml_node_type type = node_element)
        {
                if (!alloc.reserve()) return 0;

                xml_node_struct* child = allocate_node(alloc, type);
                if (!child) return 0;

                append_node(child, node);

                return child;
        }

        PUGI__FN_NO_INLINE xml_attribute_struct* append_new_attribute(xml_node_struct* node, xml_allocator& alloc)
        {
                if (!alloc.reserve()) return 0;

                xml_attribute_struct* attr = allocate_attribute(alloc);
                if (!attr) return 0;

                append_attribute(attr, node);

                return attr;
        }
PUGI__NS_END

// Helper classes for code generation
PUGI__NS_BEGIN
        struct opt_false
        {
                enum { value = 0 };
        };

        struct opt_true
        {
                enum { value = 1 };
        };
PUGI__NS_END

// Unicode utilities
PUGI__NS_BEGIN
        inline uint16_t endian_swap(uint16_t value)
        {
                return static_cast<uint16_t>(((value & 0xff) << 8) | (value >> 8));
        }

        inline uint32_t endian_swap(uint32_t value)
        {
                return ((value & 0xff) << 24) | ((value & 0xff00) << 8) | ((value & 0xff0000) >> 8) | (value >> 24);
        }

        struct utf8_counter
        {
                typedef size_t value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        // U+0000..U+007F
                        if (ch < 0x80) return result + 1;
                        // U+0080..U+07FF
                        else if (ch < 0x800) return result + 2;
                        // U+0800..U+FFFF
                        else return result + 3;
                }

                static value_type high(value_type result, uint32_t)
                {
                        // U+10000..U+10FFFF
                        return result + 4;
                }
        };

        struct utf8_writer
        {
                typedef uint8_t* value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        // U+0000..U+007F
                        if (ch < 0x80)
                        {
                                *result = static_cast<uint8_t>(ch);
                                return result + 1;
                        }
                        // U+0080..U+07FF
                        else if (ch < 0x800)
                        {
                                result[0] = static_cast<uint8_t>(0xC0 | (ch >> 6));
                                result[1] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
                                return result + 2;
                        }
                        // U+0800..U+FFFF
                        else
                        {
                                result[0] = static_cast<uint8_t>(0xE0 | (ch >> 12));
                                result[1] = static_cast<uint8_t>(0x80 | ((ch >> 6) & 0x3F));
                                result[2] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
                                return result + 3;
                        }
                }

                static value_type high(value_type result, uint32_t ch)
                {
                        // U+10000..U+10FFFF
                        result[0] = static_cast<uint8_t>(0xF0 | (ch >> 18));
                        result[1] = static_cast<uint8_t>(0x80 | ((ch >> 12) & 0x3F));
                        result[2] = static_cast<uint8_t>(0x80 | ((ch >> 6) & 0x3F));
                        result[3] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
                        return result + 4;
                }

                static value_type any(value_type result, uint32_t ch)
                {
                        return (ch < 0x10000) ? low(result, ch) : high(result, ch);
                }
        };

        struct utf16_counter
        {
                typedef size_t value_type;

                static value_type low(value_type result, uint32_t)
                {
                        return result + 1;
                }

                static value_type high(value_type result, uint32_t)
                {
                        return result + 2;
                }
        };

        struct utf16_writer
        {
                typedef uint16_t* value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        *result = static_cast<uint16_t>(ch);

                        return result + 1;
                }

                static value_type high(value_type result, uint32_t ch)
                {
                        uint32_t msh = static_cast<uint32_t>(ch - 0x10000) >> 10;
                        uint32_t lsh = static_cast<uint32_t>(ch - 0x10000) & 0x3ff;

                        result[0] = static_cast<uint16_t>(0xD800 + msh);
                        result[1] = static_cast<uint16_t>(0xDC00 + lsh);

                        return result + 2;
                }

                static value_type any(value_type result, uint32_t ch)
                {
                        return (ch < 0x10000) ? low(result, ch) : high(result, ch);
                }
        };

        struct utf32_counter
        {
                typedef size_t value_type;

                static value_type low(value_type result, uint32_t)
                {
                        return result + 1;
                }

                static value_type high(value_type result, uint32_t)
                {
                        return result + 1;
                }
        };

        struct utf32_writer
        {
                typedef uint32_t* value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        *result = ch;

                        return result + 1;
                }

                static value_type high(value_type result, uint32_t ch)
                {
                        *result = ch;

                        return result + 1;
                }

                static value_type any(value_type result, uint32_t ch)
                {
                        *result = ch;

                        return result + 1;
                }
        };

        struct latin1_writer
        {
                typedef uint8_t* value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        *result = static_cast<uint8_t>(ch > 255 ? '?' : ch);

                        return result + 1;
                }

                static value_type high(value_type result, uint32_t ch)
                {
                        (void)ch;

                        *result = '?';

                        return result + 1;
                }
        };

        struct utf8_decoder
        {
                typedef uint8_t type;

                template <typename Traits> static inline typename Traits::value_type process(const uint8_t* data, size_t size, typename Traits::value_type result, Traits)
                {
                        const uint8_t utf8_byte_mask = 0x3f;

                        while (size)
                        {
                                uint8_t lead = *data;

                                // 0xxxxxxx -> U+0000..U+007F
                                if (lead < 0x80)
                                {
                                        result = Traits::low(result, lead);
                                        data += 1;
                                        size -= 1;

                                        // process aligned single-byte (ascii) blocks
                                        if ((reinterpret_cast<uintptr_t>(data) & 3) == 0)
                                        {
                                                // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                                                while (size >= 4 && (*static_cast<const uint32_t*>(static_cast<const void*>(data)) & 0x80808080) == 0)
                                                {
                                                        result = Traits::low(result, data[0]);
                                                        result = Traits::low(result, data[1]);
                                                        result = Traits::low(result, data[2]);
                                                        result = Traits::low(result, data[3]);
                                                        data += 4;
                                                        size -= 4;
                                                }
                                        }
                                }
                                // 110xxxxx -> U+0080..U+07FF
                                else if (static_cast<unsigned int>(lead - 0xC0) < 0x20 && size >= 2 && (data[1] & 0xc0) == 0x80)
                                {
                                        result = Traits::low(result, ((lead & ~0xC0) << 6) | (data[1] & utf8_byte_mask));
                                        data += 2;
                                        size -= 2;
                                }
                                // 1110xxxx -> U+0800-U+FFFF
                                else if (static_cast<unsigned int>(lead - 0xE0) < 0x10 && size >= 3 && (data[1] & 0xc0) == 0x80 && (data[2] & 0xc0) == 0x80)
                                {
                                        result = Traits::low(result, ((lead & ~0xE0) << 12) | ((data[1] & utf8_byte_mask) << 6) | (data[2] & utf8_byte_mask));
                                        data += 3;
                                        size -= 3;
                                }
                                // 11110xxx -> U+10000..U+10FFFF
                                else if (static_cast<unsigned int>(lead - 0xF0) < 0x08 && size >= 4 && (data[1] & 0xc0) == 0x80 && (data[2] & 0xc0) == 0x80 && (data[3] & 0xc0) == 0x80)
                                {
                                        result = Traits::high(result, ((lead & ~0xF0) << 18) | ((data[1] & utf8_byte_mask) << 12) | ((data[2] & utf8_byte_mask) << 6) | (data[3] & utf8_byte_mask));
                                        data += 4;
                                        size -= 4;
                                }
                                // 10xxxxxx or 11111xxx -> invalid
                                else
                                {
                                        data += 1;
                                        size -= 1;
                                }
                        }

                        return result;
                }
        };

        template <typename opt_swap> struct utf16_decoder
        {
                typedef uint16_t type;

                template <typename Traits> static inline typename Traits::value_type process(const uint16_t* data, size_t size, typename Traits::value_type result, Traits)
                {
                        while (size)
                        {
                                uint16_t lead = opt_swap::value ? endian_swap(*data) : *data;

                                // U+0000..U+D7FF
                                if (lead < 0xD800)
                                {
                                        result = Traits::low(result, lead);
                                        data += 1;
                                        size -= 1;
                                }
                                // U+E000..U+FFFF
                                else if (static_cast<unsigned int>(lead - 0xE000) < 0x2000)
                                {
                                        result = Traits::low(result, lead);
                                        data += 1;
                                        size -= 1;
                                }
                                // surrogate pair lead
                                else if (static_cast<unsigned int>(lead - 0xD800) < 0x400 && size >= 2)
                                {
                                        uint16_t next = opt_swap::value ? endian_swap(data[1]) : data[1];

                                        if (static_cast<unsigned int>(next - 0xDC00) < 0x400)
                                        {
                                                result = Traits::high(result, 0x10000 + ((lead & 0x3ff) << 10) + (next & 0x3ff));
                                                data += 2;
                                                size -= 2;
                                        }
                                        else
                                        {
                                                data += 1;
                                                size -= 1;
                                        }
                                }
                                else
                                {
                                        data += 1;
                                        size -= 1;
                                }
                        }

                        return result;
                }
        };

        template <typename opt_swap> struct utf32_decoder
        {
                typedef uint32_t type;

                template <typename Traits> static inline typename Traits::value_type process(const uint32_t* data, size_t size, typename Traits::value_type result, Traits)
                {
                        while (size)
                        {
                                uint32_t lead = opt_swap::value ? endian_swap(*data) : *data;

                                // U+0000..U+FFFF
                                if (lead < 0x10000)
                                {
                                        result = Traits::low(result, lead);
                                        data += 1;
                                        size -= 1;
                                }
                                // U+10000..U+10FFFF
                                else
                                {
                                        result = Traits::high(result, lead);
                                        data += 1;
                                        size -= 1;
                                }
                        }

                        return result;
                }
        };

        struct latin1_decoder
        {
                typedef uint8_t type;

                template <typename Traits> static inline typename Traits::value_type process(const uint8_t* data, size_t size, typename Traits::value_type result, Traits)
                {
                        while (size)
                        {
                                result = Traits::low(result, *data);
                                data += 1;
                                size -= 1;
                        }

                        return result;
                }
        };

        template <size_t size> struct wchar_selector;

        template <> struct wchar_selector<2>
        {
                typedef uint16_t type;
                typedef utf16_counter counter;
                typedef utf16_writer writer;
                typedef utf16_decoder<opt_false> decoder;
        };

        template <> struct wchar_selector<4>
        {
                typedef uint32_t type;
                typedef utf32_counter counter;
                typedef utf32_writer writer;
                typedef utf32_decoder<opt_false> decoder;
        };

        typedef wchar_selector<sizeof(wchar_t)>::counter wchar_counter;
        typedef wchar_selector<sizeof(wchar_t)>::writer wchar_writer;

        struct wchar_decoder
        {
                typedef wchar_t type;

                template <typename Traits> static inline typename Traits::value_type process(const wchar_t* data, size_t size, typename Traits::value_type result, Traits traits)
                {
                        typedef wchar_selector<sizeof(wchar_t)>::decoder decoder;

                        return decoder::process(reinterpret_cast<const typename decoder::type*>(data), size, result, traits);
                }
        };

#ifdef PUGIXML_WCHAR_MODE
        PUGI__FN void convert_wchar_endian_swap(wchar_t* result, const wchar_t* data, size_t length)
        {
                for (size_t i = 0; i < length; ++i)
                        result[i] = static_cast<wchar_t>(endian_swap(static_cast<wchar_selector<sizeof(wchar_t)>::type>(data[i])));
        }
#endif
PUGI__NS_END

PUGI__NS_BEGIN
        enum chartype_t
        {
                ct_parse_pcdata = 1,    // \0, &, \r, <
                ct_parse_attr = 2,              // \0, &, \r, ', "
                ct_parse_attr_ws = 4,   // \0, &, \r, ', ", \n, tab
                ct_space = 8,                   // \r, \n, space, tab
                ct_parse_cdata = 16,    // \0, ], >, \r
                ct_parse_comment = 32,  // \0, -, >, \r
                ct_symbol = 64,                 // Any symbol > 127, a-z, A-Z, 0-9, _, :, -, .
                ct_start_symbol = 128   // Any symbol > 127, a-z, A-Z, _, :
        };

        static const unsigned char chartype_table[256] =
        {
                55,  0,   0,   0,   0,   0,   0,   0,      0,   12,  12,  0,   0,   63,  0,   0,   // 0-15
                0,   0,   0,   0,   0,   0,   0,   0,      0,   0,   0,   0,   0,   0,   0,   0,   // 16-31
                8,   0,   6,   0,   0,   0,   7,   6,      0,   0,   0,   0,   0,   96,  64,  0,   // 32-47
                64,  64,  64,  64,  64,  64,  64,  64,     64,  64,  192, 0,   1,   0,   48,  0,   // 48-63
                0,   192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192, // 64-79
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 0,   0,   16,  0,   192, // 80-95
                0,   192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192, // 96-111
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 0, 0, 0, 0, 0,           // 112-127

                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192, // 128+
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192
        };

        enum chartypex_t
        {
                ctx_special_pcdata = 1,   // Any symbol >= 0 and < 32 (except \t, \r, \n), &, <, >
                ctx_special_attr = 2,     // Any symbol >= 0 and < 32 (except \t), &, <, >, "
                ctx_start_symbol = 4,     // Any symbol > 127, a-z, A-Z, _
                ctx_digit = 8,                    // 0-9
                ctx_symbol = 16                   // Any symbol > 127, a-z, A-Z, 0-9, _, -, .
        };

        static const unsigned char chartypex_table[256] =
        {
                3,  3,  3,  3,  3,  3,  3,  3,     3,  0,  2,  3,  3,  2,  3,  3,     // 0-15
                3,  3,  3,  3,  3,  3,  3,  3,     3,  3,  3,  3,  3,  3,  3,  3,     // 16-31
                0,  0,  2,  0,  0,  0,  3,  0,     0,  0,  0,  0,  0, 16, 16,  0,     // 32-47
                24, 24, 24, 24, 24, 24, 24, 24,    24, 24, 0,  0,  3,  0,  3,  0,     // 48-63

                0,  20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,    // 64-79
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 0,  0,  0,  0,  20,    // 80-95
                0,  20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,    // 96-111
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 0,  0,  0,  0,  0,     // 112-127

                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,    // 128+
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20
        };

#ifdef PUGIXML_WCHAR_MODE
        #define PUGI__IS_CHARTYPE_IMPL(c, ct, table) ((static_cast<unsigned int>(c) < 128 ? table[static_cast<unsigned int>(c)] : table[128]) & (ct))
#else
        #define PUGI__IS_CHARTYPE_IMPL(c, ct, table) (table[static_cast<unsigned char>(c)] & (ct))
#endif

        #define PUGI__IS_CHARTYPE(c, ct) PUGI__IS_CHARTYPE_IMPL(c, ct, chartype_table)
        #define PUGI__IS_CHARTYPEX(c, ct) PUGI__IS_CHARTYPE_IMPL(c, ct, chartypex_table)

        PUGI__FN bool is_little_endian()
        {
                unsigned int ui = 1;

                return *reinterpret_cast<unsigned char*>(&ui) == 1;
        }

        PUGI__FN xml_encoding get_wchar_encoding()
        {
                PUGI__STATIC_ASSERT(sizeof(wchar_t) == 2 || sizeof(wchar_t) == 4);

                if (sizeof(wchar_t) == 2)
                        return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;
                else
                        return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;
        }

        PUGI__FN bool parse_declaration_encoding(const uint8_t* data, size_t size, const uint8_t*& out_encoding, size_t& out_length)
        {
        #define PUGI__SCANCHAR(ch) { if (offset >= size || data[offset] != ch) return false; offset++; }
        #define PUGI__SCANCHARTYPE(ct) { while (offset < size && PUGI__IS_CHARTYPE(data[offset], ct)) offset++; }

                // check if we have a non-empty XML declaration
                if (size < 6 || !((data[0] == '<') & (data[1] == '?') & (data[2] == 'x') & (data[3] == 'm') & (data[4] == 'l') && PUGI__IS_CHARTYPE(data[5], ct_space)))
                        return false;

                // scan XML declaration until the encoding field
                for (size_t i = 6; i + 1 < size; ++i)
                {
                        // declaration can not contain ? in quoted values
                        if (data[i] == '?')
                                return false;

                        if (data[i] == 'e' && data[i + 1] == 'n')
                        {
                                size_t offset = i;

                                // encoding follows the version field which can't contain 'en' so this has to be the encoding if XML is well formed
                                PUGI__SCANCHAR('e'); PUGI__SCANCHAR('n'); PUGI__SCANCHAR('c'); PUGI__SCANCHAR('o');
                                PUGI__SCANCHAR('d'); PUGI__SCANCHAR('i'); PUGI__SCANCHAR('n'); PUGI__SCANCHAR('g');

                                // S? = S?
                                PUGI__SCANCHARTYPE(ct_space);
                                PUGI__SCANCHAR('=');
                                PUGI__SCANCHARTYPE(ct_space);

                                // the only two valid delimiters are ' and "
                                uint8_t delimiter = (offset < size && data[offset] == '"') ? '"' : '\'';

                                PUGI__SCANCHAR(delimiter);

                                size_t start = offset;

                                out_encoding = data + offset;

                                PUGI__SCANCHARTYPE(ct_symbol);

                                out_length = offset - start;

                                PUGI__SCANCHAR(delimiter);

                                return true;
                        }
                }

                return false;

        #undef PUGI__SCANCHAR
        #undef PUGI__SCANCHARTYPE
        }

        PUGI__FN xml_encoding guess_buffer_encoding(const uint8_t* data, size_t size)
        {
                // skip encoding autodetection if input buffer is too small
                if (size < 4) return encoding_utf8;

                uint8_t d0 = data[0], d1 = data[1], d2 = data[2], d3 = data[3];

                // look for BOM in first few bytes
                if (d0 == 0 && d1 == 0 && d2 == 0xfe && d3 == 0xff) return encoding_utf32_be;
                if (d0 == 0xff && d1 == 0xfe && d2 == 0 && d3 == 0) return encoding_utf32_le;
                if (d0 == 0xfe && d1 == 0xff) return encoding_utf16_be;
                if (d0 == 0xff && d1 == 0xfe) return encoding_utf16_le;
                if (d0 == 0xef && d1 == 0xbb && d2 == 0xbf) return encoding_utf8;

                // look for <, <? or <?xm in various encodings
                if (d0 == 0 && d1 == 0 && d2 == 0 && d3 == 0x3c) return encoding_utf32_be;
                if (d0 == 0x3c && d1 == 0 && d2 == 0 && d3 == 0) return encoding_utf32_le;
                if (d0 == 0 && d1 == 0x3c && d2 == 0 && d3 == 0x3f) return encoding_utf16_be;
                if (d0 == 0x3c && d1 == 0 && d2 == 0x3f && d3 == 0) return encoding_utf16_le;

                // look for utf16 < followed by node name (this may fail, but is better than utf8 since it's zero terminated so early)
                if (d0 == 0 && d1 == 0x3c) return encoding_utf16_be;
                if (d0 == 0x3c && d1 == 0) return encoding_utf16_le;

                // no known BOM detected; parse declaration
                const uint8_t* enc = 0;
                size_t enc_length = 0;

                if (d0 == 0x3c && d1 == 0x3f && d2 == 0x78 && d3 == 0x6d && parse_declaration_encoding(data, size, enc, enc_length))
                {
                        // iso-8859-1 (case-insensitive)
                        if (enc_length == 10
                                && (enc[0] | ' ') == 'i' && (enc[1] | ' ') == 's' && (enc[2] | ' ') == 'o'
                                && enc[3] == '-' && enc[4] == '8' && enc[5] == '8' && enc[6] == '5' && enc[7] == '9'
                                && enc[8] == '-' && enc[9] == '1')
                                return encoding_latin1;

                        // latin1 (case-insensitive)
                        if (enc_length == 6
                                && (enc[0] | ' ') == 'l' && (enc[1] | ' ') == 'a' && (enc[2] | ' ') == 't'
                                && (enc[3] | ' ') == 'i' && (enc[4] | ' ') == 'n'
                                && enc[5] == '1')
                                return encoding_latin1;
                }

                return encoding_utf8;
        }

        PUGI__FN xml_encoding get_buffer_encoding(xml_encoding encoding, const void* contents, size_t size)
        {
                // replace wchar encoding with utf implementation
                if (encoding == encoding_wchar) return get_wchar_encoding();

                // replace utf16 encoding with utf16 with specific endianness
                if (encoding == encoding_utf16) return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                // replace utf32 encoding with utf32 with specific endianness
                if (encoding == encoding_utf32) return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                // only do autodetection if no explicit encoding is requested
                if (encoding != encoding_auto) return encoding;

                // try to guess encoding (based on XML specification, Appendix F.1)
                const uint8_t* data = static_cast<const uint8_t*>(contents);

                return guess_buffer_encoding(data, size);
        }

        PUGI__FN bool get_mutable_buffer(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
        {
                size_t length = size / sizeof(char_t);

                if (is_mutable)
                {
                        out_buffer = static_cast<char_t*>(const_cast<void*>(contents));
                        out_length = length;
                }
                else
                {
                        char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                        if (!buffer) return false;

                        if (contents)
                                memcpy(buffer, contents, length * sizeof(char_t));
                        else
                                assert(length == 0);

                        buffer[length] = 0;

                        out_buffer = buffer;
                        out_length = length + 1;
                }

                return true;
        }

#ifdef PUGIXML_WCHAR_MODE
        PUGI__FN bool need_endian_swap_utf(xml_encoding le, xml_encoding re)
        {
                return (le == encoding_utf16_be && re == encoding_utf16_le) || (le == encoding_utf16_le && re == encoding_utf16_be) ||
                           (le == encoding_utf32_be && re == encoding_utf32_le) || (le == encoding_utf32_le && re == encoding_utf32_be);
        }

        PUGI__FN bool convert_buffer_endian_swap(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
        {
                const char_t* data = static_cast<const char_t*>(contents);
                size_t length = size / sizeof(char_t);

                if (is_mutable)
                {
                        char_t* buffer = const_cast<char_t*>(data);

                        convert_wchar_endian_swap(buffer, data, length);

                        out_buffer = buffer;
                        out_length = length;
                }
                else
                {
                        char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                        if (!buffer) return false;

                        convert_wchar_endian_swap(buffer, data, length);
                        buffer[length] = 0;

                        out_buffer = buffer;
                        out_length = length + 1;
                }

                return true;
        }

        template <typename D> PUGI__FN bool convert_buffer_generic(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, D)
        {
                const typename D::type* data = static_cast<const typename D::type*>(contents);
                size_t data_length = size / sizeof(typename D::type);

                // first pass: get length in wchar_t units
                size_t length = D::process(data, data_length, 0, wchar_counter());

                // allocate buffer of suitable length
                char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                if (!buffer) return false;

                // second pass: convert utf16 input to wchar_t
                wchar_writer::value_type obegin = reinterpret_cast<wchar_writer::value_type>(buffer);
                wchar_writer::value_type oend = D::process(data, data_length, obegin, wchar_writer());

                assert(oend == obegin + length);
                *oend = 0;

                out_buffer = buffer;
                out_length = length + 1;

                return true;
        }

        PUGI__FN bool convert_buffer(char_t*& out_buffer, size_t& out_length, xml_encoding encoding, const void* contents, size_t size, bool is_mutable)
        {
                // get native encoding
                xml_encoding wchar_encoding = get_wchar_encoding();

                // fast path: no conversion required
                if (encoding == wchar_encoding)
                        return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

                // only endian-swapping is required
                if (need_endian_swap_utf(encoding, wchar_encoding))
                        return convert_buffer_endian_swap(out_buffer, out_length, contents, size, is_mutable);

                // source encoding is utf8
                if (encoding == encoding_utf8)
                        return convert_buffer_generic(out_buffer, out_length, contents, size, utf8_decoder());

                // source encoding is utf16
                if (encoding == encoding_utf16_be || encoding == encoding_utf16_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                        return (native_encoding == encoding) ?
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_false>()) :
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_true>());
                }

                // source encoding is utf32
                if (encoding == encoding_utf32_be || encoding == encoding_utf32_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                        return (native_encoding == encoding) ?
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_false>()) :
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_true>());
                }

                // source encoding is latin1
                if (encoding == encoding_latin1)
                        return convert_buffer_generic(out_buffer, out_length, contents, size, latin1_decoder());

                assert(false && "Invalid encoding");
                return false;
        }
#else
        template <typename D> PUGI__FN bool convert_buffer_generic(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, D)
        {
                const typename D::type* data = static_cast<const typename D::type*>(contents);
                size_t data_length = size / sizeof(typename D::type);

                // first pass: get length in utf8 units
                size_t length = D::process(data, data_length, 0, utf8_counter());

                // allocate buffer of suitable length
                char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                if (!buffer) return false;

                // second pass: convert utf16 input to utf8
                uint8_t* obegin = reinterpret_cast<uint8_t*>(buffer);
                uint8_t* oend = D::process(data, data_length, obegin, utf8_writer());

                assert(oend == obegin + length);
                *oend = 0;

                out_buffer = buffer;
                out_length = length + 1;

                return true;
        }

        PUGI__FN size_t get_latin1_7bit_prefix_length(const uint8_t* data, size_t size)
        {
                for (size_t i = 0; i < size; ++i)
                        if (data[i] > 127)
                                return i;

                return size;
        }

        PUGI__FN bool convert_buffer_latin1(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
        {
                const uint8_t* data = static_cast<const uint8_t*>(contents);
                size_t data_length = size;

                // get size of prefix that does not need utf8 conversion
                size_t prefix_length = get_latin1_7bit_prefix_length(data, data_length);
                assert(prefix_length <= data_length);

                const uint8_t* postfix = data + prefix_length;
                size_t postfix_length = data_length - prefix_length;

                // if no conversion is needed, just return the original buffer
                if (postfix_length == 0) return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

                // first pass: get length in utf8 units
                size_t length = prefix_length + latin1_decoder::process(postfix, postfix_length, 0, utf8_counter());

                // allocate buffer of suitable length
                char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                if (!buffer) return false;

                // second pass: convert latin1 input to utf8
                memcpy(buffer, data, prefix_length);

                uint8_t* obegin = reinterpret_cast<uint8_t*>(buffer);
                uint8_t* oend = latin1_decoder::process(postfix, postfix_length, obegin + prefix_length, utf8_writer());

                assert(oend == obegin + length);
                *oend = 0;

                out_buffer = buffer;
                out_length = length + 1;

                return true;
        }

        PUGI__FN bool convert_buffer(char_t*& out_buffer, size_t& out_length, xml_encoding encoding, const void* contents, size_t size, bool is_mutable)
        {
                // fast path: no conversion required
                if (encoding == encoding_utf8)
                        return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

                // source encoding is utf16
                if (encoding == encoding_utf16_be || encoding == encoding_utf16_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                        return (native_encoding == encoding) ?
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_false>()) :
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_true>());
                }

                // source encoding is utf32
                if (encoding == encoding_utf32_be || encoding == encoding_utf32_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                        return (native_encoding == encoding) ?
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_false>()) :
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_true>());
                }

                // source encoding is latin1
                if (encoding == encoding_latin1)
                        return convert_buffer_latin1(out_buffer, out_length, contents, size, is_mutable);

                assert(false && "Invalid encoding");
                return false;
        }
#endif

        PUGI__FN size_t as_utf8_begin(const wchar_t* str, size_t length)
        {
                // get length in utf8 characters
                return wchar_decoder::process(str, length, 0, utf8_counter());
        }

        PUGI__FN void as_utf8_end(char* buffer, size_t size, const wchar_t* str, size_t length)
        {
                // convert to utf8
                uint8_t* begin = reinterpret_cast<uint8_t*>(buffer);
                uint8_t* end = wchar_decoder::process(str, length, begin, utf8_writer());

                assert(begin + size == end);
                (void)!end;
                (void)!size;
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN std::string as_utf8_impl(const wchar_t* str, size_t length)
        {
                // first pass: get length in utf8 characters
                size_t size = as_utf8_begin(str, length);

                // allocate resulting string
                std::string result;
                result.resize(size);

                // second pass: convert to utf8
                if (size > 0) as_utf8_end(&result[0], size, str, length);

                return result;
        }

        PUGI__FN std::basic_string<wchar_t> as_wide_impl(const char* str, size_t size)
        {
                const uint8_t* data = reinterpret_cast<const uint8_t*>(str);

                // first pass: get length in wchar_t units
                size_t length = utf8_decoder::process(data, size, 0, wchar_counter());

                // allocate resulting string
                std::basic_string<wchar_t> result;
                result.resize(length);

                // second pass: convert to wchar_t
                if (length > 0)
                {
                        wchar_writer::value_type begin = reinterpret_cast<wchar_writer::value_type>(&result[0]);
                        wchar_writer::value_type end = utf8_decoder::process(data, size, begin, wchar_writer());

                        assert(begin + length == end);
                        (void)!end;
                }

                return result;
        }
#endif

        template <typename Header>
        inline bool strcpy_insitu_allow(size_t length, const Header& header, uintptr_t header_mask, char_t* target)
        {
                // never reuse shared memory
                if (header & xml_memory_page_contents_shared_mask) return false;

                size_t target_length = strlength(target);

                // always reuse document buffer memory if possible
                if ((header & header_mask) == 0) return target_length >= length;

                // reuse heap memory if waste is not too great
                const size_t reuse_threshold = 32;

                return target_length >= length && (target_length < reuse_threshold || target_length - length < target_length / 2);
        }

        template <typename String, typename Header>
        PUGI__FN bool strcpy_insitu(String& dest, Header& header, uintptr_t header_mask, const char_t* source, size_t source_length)
        {
                if (source_length == 0)
                {
                        // empty string and null pointer are equivalent, so just deallocate old memory
                        xml_allocator* alloc = PUGI__GETPAGE_IMPL(header)->allocator;

                        if (header & header_mask) alloc->deallocate_string(dest);

                        // mark the string as not allocated
                        dest = 0;
                        header &= ~header_mask;

                        return true;
                }
                else if (dest && strcpy_insitu_allow(source_length, header, header_mask, dest))
                {
                        // we can reuse old buffer, so just copy the new data (including zero terminator)
                        memcpy(dest, source, source_length * sizeof(char_t));
                        dest[source_length] = 0;

                        return true;
                }
                else
                {
                        xml_allocator* alloc = PUGI__GETPAGE_IMPL(header)->allocator;

                        if (!alloc->reserve()) return false;

                        // allocate new buffer
                        char_t* buf = alloc->allocate_string(source_length + 1);
                        if (!buf) return false;

                        // copy the string (including zero terminator)
                        memcpy(buf, source, source_length * sizeof(char_t));
                        buf[source_length] = 0;

                        // deallocate old buffer (*after* the above to protect against overlapping memory and/or allocation failures)
                        if (header & header_mask) alloc->deallocate_string(dest);

                        // the string is now allocated, so set the flag
                        dest = buf;
                        header |= header_mask;

                        return true;
                }
        }

        struct gap
        {
                char_t* end;
                size_t size;

                gap(): end(0), size(0)
                {
                }

                // Push new gap, move s count bytes further (skipping the gap).
                // Collapse previous gap.
                void push(char_t*& s, size_t count)
                {
                        if (end) // there was a gap already; collapse it
                        {
                                // Move [old_gap_end, new_gap_start) to [old_gap_start, ...)
                                assert(s >= end);
                                memmove(end - size, end, reinterpret_cast<char*>(s) - reinterpret_cast<char*>(end));
                        }

                        s += count; // end of current gap

                        // "merge" two gaps
                        end = s;
                        size += count;
                }

                // Collapse all gaps, return past-the-end pointer
                char_t* flush(char_t* s)
                {
                        if (end)
                        {
                                // Move [old_gap_end, current_pos) to [old_gap_start, ...)
                                assert(s >= end);
                                memmove(end - size, end, reinterpret_cast<char*>(s) - reinterpret_cast<char*>(end));

                                return s - size;
                        }
                        else return s;
                }
        };

        PUGI__FN char_t* strconv_escape(char_t* s, gap& g)
        {
                char_t* stre = s + 1;

                switch (*stre)
                {
                        case '#':       // &#...
                        {
                                unsigned int ucsc = 0;

                                if (stre[1] == 'x') // &#x... (hex code)
                                {
                                        stre += 2;

                                        char_t ch = *stre;

                                        if (ch == ';') return stre;

                                        for (;;)
                                        {
                                                if (static_cast<unsigned int>(ch - '0') <= 9)
                                                        ucsc = 16 * ucsc + (ch - '0');
                                                else if (static_cast<unsigned int>((ch | ' ') - 'a') <= 5)
                                                        ucsc = 16 * ucsc + ((ch | ' ') - 'a' + 10);
                                                else if (ch == ';')
                                                        break;
                                                else // cancel
                                                        return stre;

                                                ch = *++stre;
                                        }

                                        ++stre;
                                }
                                else    // &#... (dec code)
                                {
                                        char_t ch = *++stre;

                                        if (ch == ';') return stre;

                                        for (;;)
                                        {
                                                if (static_cast<unsigned int>(static_cast<unsigned int>(ch) - '0') <= 9)
                                                        ucsc = 10 * ucsc + (ch - '0');
                                                else if (ch == ';')
                                                        break;
                                                else // cancel
                                                        return stre;

                                                ch = *++stre;
                                        }

                                        ++stre;
                                }

                        #ifdef PUGIXML_WCHAR_MODE
                                s = reinterpret_cast<char_t*>(wchar_writer::any(reinterpret_cast<wchar_writer::value_type>(s), ucsc));
                        #else
                                s = reinterpret_cast<char_t*>(utf8_writer::any(reinterpret_cast<uint8_t*>(s), ucsc));
                        #endif

                                g.push(s, stre - s);
                                return stre;
                        }

                        case 'a':       // &a
                        {
                                ++stre;

                                if (*stre == 'm') // &am
                                {
                                        if (*++stre == 'p' && *++stre == ';') // &amp;
                                        {
                                                *s++ = '&';
                                                ++stre;

                                                g.push(s, stre - s);
                                                return stre;
                                        }
                                }
                                else if (*stre == 'p') // &ap
                                {
                                        if (*++stre == 'o' && *++stre == 's' && *++stre == ';') // &apos;
                                        {
                                                *s++ = '\'';
                                                ++stre;

                                                g.push(s, stre - s);
                                                return stre;
                                        }
                                }
                                break;
                        }

                        case 'g': // &g
                        {
                                if (*++stre == 't' && *++stre == ';') // &gt;
                                {
                                        *s++ = '>';
                                        ++stre;

                                        g.push(s, stre - s);
                                        return stre;
                                }
                                break;
                        }

                        case 'l': // &l
                        {
                                if (*++stre == 't' && *++stre == ';') // &lt;
                                {
                                        *s++ = '<';
                                        ++stre;

                                        g.push(s, stre - s);
                                        return stre;
                                }
                                break;
                        }

                        case 'q': // &q
                        {
                                if (*++stre == 'u' && *++stre == 'o' && *++stre == 't' && *++stre == ';') // &quot;
                                {
                                        *s++ = '"';
                                        ++stre;

                                        g.push(s, stre - s);
                                        return stre;
                                }
                                break;
                        }

                        default:
                                break;
                }

                return stre;
        }

        // Parser utilities
        #define PUGI__ENDSWITH(c, e)        ((c) == (e) || ((c) == 0 && endch == (e)))
        #define PUGI__SKIPWS()              { while (PUGI__IS_CHARTYPE(*s, ct_space)) ++s; }
        #define PUGI__OPTSET(OPT)           ( optmsk & (OPT) )
        #define PUGI__PUSHNODE(TYPE)        { cursor = append_new_node(cursor, *alloc, TYPE); if (!cursor) PUGI__THROW_ERROR(status_out_of_memory, s); }
        #define PUGI__POPNODE()             { cursor = cursor->parent; }
        #define PUGI__SCANFOR(X)            { while (*s != 0 && !(X)) ++s; }
        #define PUGI__SCANWHILE(X)          { while (X) ++s; }
        #define PUGI__SCANWHILE_UNROLL(X)   { for (;;) { char_t ss = s[0]; if (PUGI__UNLIKELY(!(X))) { break; } ss = s[1]; if (PUGI__UNLIKELY(!(X))) { s += 1; break; } ss = s[2]; if (PUGI__UNLIKELY(!(X))) { s += 2; break; } ss = s[3]; if (PUGI__UNLIKELY(!(X))) { s += 3; break; } s += 4; } }
        #define PUGI__ENDSEG()              { ch = *s; *s = 0; ++s; }
        #define PUGI__THROW_ERROR(err, m)   return error_offset = m, error_status = err, static_cast<char_t*>(0)
        #define PUGI__CHECK_ERROR(err, m)   { if (*s == 0) PUGI__THROW_ERROR(err, m); }

        PUGI__FN char_t* strconv_comment(char_t* s, char_t endch)
        {
                gap g;

                while (true)
                {
                        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_comment));

                        if (*s == '\r') // Either a single 0x0d or 0x0d 0x0a pair
                        {
                                *s++ = '\n'; // replace first one with 0x0a

                                if (*s == '\n') g.push(s, 1);
                        }
                        else if (s[0] == '-' && s[1] == '-' && PUGI__ENDSWITH(s[2], '>')) // comment ends here
                        {
                                *g.flush(s) = 0;

                                return s + (s[2] == '>' ? 3 : 2);
                        }
                        else if (*s == 0)
                        {
                                return 0;
                        }
                        else ++s;
                }
        }

        PUGI__FN char_t* strconv_cdata(char_t* s, char_t endch)
        {
                gap g;

                while (true)
                {
                        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_cdata));

                        if (*s == '\r') // Either a single 0x0d or 0x0d 0x0a pair
                        {
                                *s++ = '\n'; // replace first one with 0x0a

                                if (*s == '\n') g.push(s, 1);
                        }
                        else if (s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>')) // CDATA ends here
                        {
                                *g.flush(s) = 0;

                                return s + 1;
                        }
                        else if (*s == 0)
                        {
                                return 0;
                        }
                        else ++s;
                }
        }

        typedef char_t* (*strconv_pcdata_t)(char_t*);

        template <typename opt_trim, typename opt_eol, typename opt_escape> struct strconv_pcdata_impl
        {
                static char_t* parse(char_t* s)
                {
                        gap g;

                        char_t* begin = s;

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_pcdata));

                                if (*s == '<') // PCDATA ends here
                                {
                                        char_t* end = g.flush(s);

                                        if (opt_trim::value)
                                                while (end > begin && PUGI__IS_CHARTYPE(end[-1], ct_space))
                                                        --end;

                                        *end = 0;

                                        return s + 1;
                                }
                                else if (opt_eol::value && *s == '\r') // Either a single 0x0d or 0x0d 0x0a pair
                                {
                                        *s++ = '\n'; // replace first one with 0x0a

                                        if (*s == '\n') g.push(s, 1);
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (*s == 0)
                                {
                                        char_t* end = g.flush(s);

                                        if (opt_trim::value)
                                                while (end > begin && PUGI__IS_CHARTYPE(end[-1], ct_space))
                                                        --end;

                                        *end = 0;

                                        return s;
                                }
                                else ++s;
                        }
                }
        };

        PUGI__FN strconv_pcdata_t get_strconv_pcdata(unsigned int optmask)
        {
                PUGI__STATIC_ASSERT(parse_escapes == 0x10 && parse_eol == 0x20 && parse_trim_pcdata == 0x0800);

                switch (((optmask >> 4) & 3) | ((optmask >> 9) & 4)) // get bitmask for flags (eol escapes trim)
                {
                case 0: return strconv_pcdata_impl<opt_false, opt_false, opt_false>::parse;
                case 1: return strconv_pcdata_impl<opt_false, opt_false, opt_true>::parse;
                case 2: return strconv_pcdata_impl<opt_false, opt_true, opt_false>::parse;
                case 3: return strconv_pcdata_impl<opt_false, opt_true, opt_true>::parse;
                case 4: return strconv_pcdata_impl<opt_true, opt_false, opt_false>::parse;
                case 5: return strconv_pcdata_impl<opt_true, opt_false, opt_true>::parse;
                case 6: return strconv_pcdata_impl<opt_true, opt_true, opt_false>::parse;
                case 7: return strconv_pcdata_impl<opt_true, opt_true, opt_true>::parse;
                default: assert(false); return 0; // should not get here
                }
        }

        typedef char_t* (*strconv_attribute_t)(char_t*, char_t);

        template <typename opt_escape> struct strconv_attribute_impl
        {
                static char_t* parse_wnorm(char_t* s, char_t end_quote)
                {
                        gap g;

                        // trim leading whitespaces
                        if (PUGI__IS_CHARTYPE(*s, ct_space))
                        {
                                char_t* str = s;

                                do ++str;
                                while (PUGI__IS_CHARTYPE(*str, ct_space));

                                g.push(s, str - s);
                        }

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr_ws | ct_space));

                                if (*s == end_quote)
                                {
                                        char_t* str = g.flush(s);

                                        do *str-- = 0;
                                        while (PUGI__IS_CHARTYPE(*str, ct_space));

                                        return s + 1;
                                }
                                else if (PUGI__IS_CHARTYPE(*s, ct_space))
                                {
                                        *s++ = ' ';

                                        if (PUGI__IS_CHARTYPE(*s, ct_space))
                                        {
                                                char_t* str = s + 1;
                                                while (PUGI__IS_CHARTYPE(*str, ct_space)) ++str;

                                                g.push(s, str - s);
                                        }
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (!*s)
                                {
                                        return 0;
                                }
                                else ++s;
                        }
                }

                static char_t* parse_wconv(char_t* s, char_t end_quote)
                {
                        gap g;

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr_ws));

                                if (*s == end_quote)
                                {
                                        *g.flush(s) = 0;

                                        return s + 1;
                                }
                                else if (PUGI__IS_CHARTYPE(*s, ct_space))
                                {
                                        if (*s == '\r')
                                        {
                                                *s++ = ' ';

                                                if (*s == '\n') g.push(s, 1);
                                        }
                                        else *s++ = ' ';
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (!*s)
                                {
                                        return 0;
                                }
                                else ++s;
                        }
                }

                static char_t* parse_eol(char_t* s, char_t end_quote)
                {
                        gap g;

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr));

                                if (*s == end_quote)
                                {
                                        *g.flush(s) = 0;

                                        return s + 1;
                                }
                                else if (*s == '\r')
                                {
                                        *s++ = '\n';

                                        if (*s == '\n') g.push(s, 1);
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (!*s)
                                {
                                        return 0;
                                }
                                else ++s;
                        }
                }

                static char_t* parse_simple(char_t* s, char_t end_quote)
                {
                        gap g;

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr));

                                if (*s == end_quote)
                                {
                                        *g.flush(s) = 0;

                                        return s + 1;
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (!*s)
                                {
                                        return 0;
                                }
                                else ++s;
                        }
                }
        };

        PUGI__FN strconv_attribute_t get_strconv_attribute(unsigned int optmask)
        {
                PUGI__STATIC_ASSERT(parse_escapes == 0x10 && parse_eol == 0x20 && parse_wconv_attribute == 0x40 && parse_wnorm_attribute == 0x80);

                switch ((optmask >> 4) & 15) // get bitmask for flags (wconv wnorm eol escapes)
                {
                case 0:  return strconv_attribute_impl<opt_false>::parse_simple;
                case 1:  return strconv_attribute_impl<opt_true>::parse_simple;
                case 2:  return strconv_attribute_impl<opt_false>::parse_eol;
                case 3:  return strconv_attribute_impl<opt_true>::parse_eol;
                case 4:  return strconv_attribute_impl<opt_false>::parse_wconv;
                case 5:  return strconv_attribute_impl<opt_true>::parse_wconv;
                case 6:  return strconv_attribute_impl<opt_false>::parse_wconv;
                case 7:  return strconv_attribute_impl<opt_true>::parse_wconv;
                case 8:  return strconv_attribute_impl<opt_false>::parse_wnorm;
                case 9:  return strconv_attribute_impl<opt_true>::parse_wnorm;
                case 10: return strconv_attribute_impl<opt_false>::parse_wnorm;
                case 11: return strconv_attribute_impl<opt_true>::parse_wnorm;
                case 12: return strconv_attribute_impl<opt_false>::parse_wnorm;
                case 13: return strconv_attribute_impl<opt_true>::parse_wnorm;
                case 14: return strconv_attribute_impl<opt_false>::parse_wnorm;
                case 15: return strconv_attribute_impl<opt_true>::parse_wnorm;
                default: assert(false); return 0; // should not get here
                }
        }

        inline xml_parse_result make_parse_result(xml_parse_status status, ptrdiff_t offset = 0)
        {
                xml_parse_result result;
                result.status = status;
                result.offset = offset;

                return result;
        }

        struct xml_parser
        {
                xml_allocator* alloc;
                char_t* error_offset;
                xml_parse_status error_status;

                xml_parser(xml_allocator* alloc_): alloc(alloc_), error_offset(0), error_status(status_ok)
                {
                }

                // DOCTYPE consists of nested sections of the following possible types:
                // <!-- ... -->, <? ... ?>, "...", '...'
                // <![...]]>
                // <!...>
                // First group can not contain nested groups
                // Second group can contain nested groups of the same type
                // Third group can contain all other groups
                char_t* parse_doctype_primitive(char_t* s)
                {
                        if (*s == '"' || *s == '\'')
                        {
                                // quoted string
                                char_t ch = *s++;
                                PUGI__SCANFOR(*s == ch);
                                if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

                                s++;
                        }
                        else if (s[0] == '<' && s[1] == '?')
                        {
                                // <? ... ?>
                                s += 2;
                                PUGI__SCANFOR(s[0] == '?' && s[1] == '>'); // no need for ENDSWITH because ?> can't terminate proper doctype
                                if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

                                s += 2;
                        }
                        else if (s[0] == '<' && s[1] == '!' && s[2] == '-' && s[3] == '-')
                        {
                                s += 4;
                                PUGI__SCANFOR(s[0] == '-' && s[1] == '-' && s[2] == '>'); // no need for ENDSWITH because --> can't terminate proper doctype
                                if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

                                s += 3;
                        }
                        else PUGI__THROW_ERROR(status_bad_doctype, s);

                        return s;
                }

                char_t* parse_doctype_ignore(char_t* s)
                {
                        size_t depth = 0;

                        assert(s[0] == '<' && s[1] == '!' && s[2] == '[');
                        s += 3;

                        while (*s)
                        {
                                if (s[0] == '<' && s[1] == '!' && s[2] == '[')
                                {
                                        // nested ignore section
                                        s += 3;
                                        depth++;
                                }
                                else if (s[0] == ']' && s[1] == ']' && s[2] == '>')
                                {
                                        // ignore section end
                                        s += 3;

                                        if (depth == 0)
                                                return s;

                                        depth--;
                                }
                                else s++;
                        }

                        PUGI__THROW_ERROR(status_bad_doctype, s);
                }

                char_t* parse_doctype_group(char_t* s, char_t endch)
                {
                        size_t depth = 0;

                        assert((s[0] == '<' || s[0] == 0) && s[1] == '!');
                        s += 2;

                        while (*s)
                        {
                                if (s[0] == '<' && s[1] == '!' && s[2] != '-')
                                {
                                        if (s[2] == '[')
                                        {
                                                // ignore
                                                s = parse_doctype_ignore(s);
                                                if (!s) return s;
                                        }
                                        else
                                        {
                                                // some control group
                                                s += 2;
                                                depth++;
                                        }
                                }
                                else if (s[0] == '<' || s[0] == '"' || s[0] == '\'')
                                {
                                        // unknown tag (forbidden), or some primitive group
                                        s = parse_doctype_primitive(s);
                                        if (!s) return s;
                                }
                                else if (*s == '>')
                                {
                                        if (depth == 0)
                                                return s;

                                        depth--;
                                        s++;
                                }
                                else s++;
                        }

                        if (depth != 0 || endch != '>') PUGI__THROW_ERROR(status_bad_doctype, s);

                        return s;
                }

                char_t* parse_exclamation(char_t* s, xml_node_struct* cursor, unsigned int optmsk, char_t endch)
                {
                        // parse node contents, starting with exclamation mark
                        ++s;

                        if (*s == '-') // '<!-...'
                        {
                                ++s;

                                if (*s == '-') // '<!--...'
                                {
                                        ++s;

                                        if (PUGI__OPTSET(parse_comments))
                                        {
                                                PUGI__PUSHNODE(node_comment); // Append a new node on the tree.
                                                cursor->value = s; // Save the offset.
                                        }

                                        if (PUGI__OPTSET(parse_eol) && PUGI__OPTSET(parse_comments))
                                        {
                                                s = strconv_comment(s, endch);

                                                if (!s) PUGI__THROW_ERROR(status_bad_comment, cursor->value);
                                        }
                                        else
                                        {
                                                // Scan for terminating '-->'.
                                                PUGI__SCANFOR(s[0] == '-' && s[1] == '-' && PUGI__ENDSWITH(s[2], '>'));
                                                PUGI__CHECK_ERROR(status_bad_comment, s);

                                                if (PUGI__OPTSET(parse_comments))
                                                        *s = 0; // Zero-terminate this segment at the first terminating '-'.

                                                s += (s[2] == '>' ? 3 : 2); // Step over the '\0->'.
                                        }
                                }
                                else PUGI__THROW_ERROR(status_bad_comment, s);
                        }
                        else if (*s == '[')
                        {
                                // '<![CDATA[...'
                                if (*++s=='C' && *++s=='D' && *++s=='A' && *++s=='T' && *++s=='A' && *++s == '[')
                                {
                                        ++s;

                                        if (PUGI__OPTSET(parse_cdata))
                                        {
                                                PUGI__PUSHNODE(node_cdata); // Append a new node on the tree.
                                                cursor->value = s; // Save the offset.

                                                if (PUGI__OPTSET(parse_eol))
                                                {
                                                        s = strconv_cdata(s, endch);

                                                        if (!s) PUGI__THROW_ERROR(status_bad_cdata, cursor->value);
                                                }
                                                else
                                                {
                                                        // Scan for terminating ']]>'.
                                                        PUGI__SCANFOR(s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>'));
                                                        PUGI__CHECK_ERROR(status_bad_cdata, s);

                                                        *s++ = 0; // Zero-terminate this segment.
                                                }
                                        }
                                        else // Flagged for discard, but we still have to scan for the terminator.
                                        {
                                                // Scan for terminating ']]>'.
                                                PUGI__SCANFOR(s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>'));
                                                PUGI__CHECK_ERROR(status_bad_cdata, s);

                                                ++s;
                                        }

                                        s += (s[1] == '>' ? 2 : 1); // Step over the last ']>'.
                                }
                                else PUGI__THROW_ERROR(status_bad_cdata, s);
                        }
                        else if (s[0] == 'D' && s[1] == 'O' && s[2] == 'C' && s[3] == 'T' && s[4] == 'Y' && s[5] == 'P' && PUGI__ENDSWITH(s[6], 'E'))
                        {
                                s -= 2;

                                if (cursor->parent) PUGI__THROW_ERROR(status_bad_doctype, s);

                                char_t* mark = s + 9;

                                s = parse_doctype_group(s, endch);
                                if (!s) return s;

                                assert((*s == 0 && endch == '>') || *s == '>');
                                if (*s) *s++ = 0;

                                if (PUGI__OPTSET(parse_doctype))
                                {
                                        while (PUGI__IS_CHARTYPE(*mark, ct_space)) ++mark;

                                        PUGI__PUSHNODE(node_doctype);

                                        cursor->value = mark;
                                }
                        }
                        else if (*s == 0 && endch == '-') PUGI__THROW_ERROR(status_bad_comment, s);
                        else if (*s == 0 && endch == '[') PUGI__THROW_ERROR(status_bad_cdata, s);
                        else PUGI__THROW_ERROR(status_unrecognized_tag, s);

                        return s;
                }

                char_t* parse_question(char_t* s, xml_node_struct*& ref_cursor, unsigned int optmsk, char_t endch)
                {
                        // load into registers
                        xml_node_struct* cursor = ref_cursor;
                        char_t ch = 0;

                        // parse node contents, starting with question mark
                        ++s;

                        // read PI target
                        char_t* target = s;

                        if (!PUGI__IS_CHARTYPE(*s, ct_start_symbol)) PUGI__THROW_ERROR(status_bad_pi, s);

                        PUGI__SCANWHILE(PUGI__IS_CHARTYPE(*s, ct_symbol));
                        PUGI__CHECK_ERROR(status_bad_pi, s);

                        // determine node type; stricmp / strcasecmp is not portable
                        bool declaration = (target[0] | ' ') == 'x' && (target[1] | ' ') == 'm' && (target[2] | ' ') == 'l' && target + 3 == s;

                        if (declaration ? PUGI__OPTSET(parse_declaration) : PUGI__OPTSET(parse_pi))
                        {
                                if (declaration)
                                {
                                        // disallow non top-level declarations
                                        if (cursor->parent) PUGI__THROW_ERROR(status_bad_pi, s);

                                        PUGI__PUSHNODE(node_declaration);
                                }
                                else
                                {
                                        PUGI__PUSHNODE(node_pi);
                                }

                                cursor->name = target;

                                PUGI__ENDSEG();

                                // parse value/attributes
                                if (ch == '?')
                                {
                                        // empty node
                                        if (!PUGI__ENDSWITH(*s, '>')) PUGI__THROW_ERROR(status_bad_pi, s);
                                        s += (*s == '>');

                                        PUGI__POPNODE();
                                }
                                else if (PUGI__IS_CHARTYPE(ch, ct_space))
                                {
                                        PUGI__SKIPWS();

                                        // scan for tag end
                                        char_t* value = s;

                                        PUGI__SCANFOR(s[0] == '?' && PUGI__ENDSWITH(s[1], '>'));
                                        PUGI__CHECK_ERROR(status_bad_pi, s);

                                        if (declaration)
                                        {
                                                // replace ending ? with / so that 'element' terminates properly
                                                *s = '/';

                                                // we exit from this function with cursor at node_declaration, which is a signal to parse() to go to LOC_ATTRIBUTES
                                                s = value;
                                        }
                                        else
                                        {
                                                // store value and step over >
                                                cursor->value = value;

                                                PUGI__POPNODE();

                                                PUGI__ENDSEG();

                                                s += (*s == '>');
                                        }
                                }
                                else PUGI__THROW_ERROR(status_bad_pi, s);
                        }
                        else
                        {
                                // scan for tag end
                                PUGI__SCANFOR(s[0] == '?' && PUGI__ENDSWITH(s[1], '>'));
                                PUGI__CHECK_ERROR(status_bad_pi, s);

                                s += (s[1] == '>' ? 2 : 1);
                        }

                        // store from registers
                        ref_cursor = cursor;

                        return s;
                }

                char_t* parse_tree(char_t* s, xml_node_struct* root, unsigned int optmsk, char_t endch)
                {
                        strconv_attribute_t strconv_attribute = get_strconv_attribute(optmsk);
                        strconv_pcdata_t strconv_pcdata = get_strconv_pcdata(optmsk);

                        char_t ch = 0;
                        xml_node_struct* cursor = root;
                        char_t* mark = s;

                        while (*s != 0)
                        {
                                if (*s == '<')
                                {
                                        ++s;

                                LOC_TAG:
                                        if (PUGI__IS_CHARTYPE(*s, ct_start_symbol)) // '<#...'
                                        {
                                                PUGI__PUSHNODE(node_element); // Append a new node to the tree.

                                                cursor->name = s;

                                                PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(ss, ct_symbol)); // Scan for a terminator.
                                                PUGI__ENDSEG(); // Save char in 'ch', terminate & step over.

                                                if (ch == '>')
                                                {
                                                        // end of tag
                                                }
                                                else if (PUGI__IS_CHARTYPE(ch, ct_space))
                                                {
                                                LOC_ATTRIBUTES:
                                                        while (true)
                                                        {
                                                                PUGI__SKIPWS(); // Eat any whitespace.

                                                                if (PUGI__IS_CHARTYPE(*s, ct_start_symbol)) // <... #...
                                                                {
                                                                        xml_attribute_struct* a = append_new_attribute(cursor, *alloc); // Make space for this attribute.
                                                                        if (!a) PUGI__THROW_ERROR(status_out_of_memory, s);

                                                                        a->name = s; // Save the offset.

                                                                        PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(ss, ct_symbol)); // Scan for a terminator.
                                                                        PUGI__ENDSEG(); // Save char in 'ch', terminate & step over.

                                                                        if (PUGI__IS_CHARTYPE(ch, ct_space))
                                                                        {
                                                                                PUGI__SKIPWS(); // Eat any whitespace.

                                                                                ch = *s;
                                                                                ++s;
                                                                        }

                                                                        if (ch == '=') // '<... #=...'
                                                                        {
                                                                                PUGI__SKIPWS(); // Eat any whitespace.

                                                                                if (*s == '"' || *s == '\'') // '<... #="...'
                                                                                {
                                                                                        ch = *s; // Save quote char to avoid breaking on "''" -or- '""'.
                                                                                        ++s; // Step over the quote.
                                                                                        a->value = s; // Save the offset.

                                                                                        s = strconv_attribute(s, ch);

                                                                                        if (!s) PUGI__THROW_ERROR(status_bad_attribute, a->value);

                                                                                        // After this line the loop continues from the start;
                                                                                        // Whitespaces, / and > are ok, symbols and EOF are wrong,
                                                                                        // everything else will be detected
                                                                                        if (PUGI__IS_CHARTYPE(*s, ct_start_symbol)) PUGI__THROW_ERROR(status_bad_attribute, s);
                                                                                }
                                                                                else PUGI__THROW_ERROR(status_bad_attribute, s);
                                                                        }
                                                                        else PUGI__THROW_ERROR(status_bad_attribute, s);
                                                                }
                                                                else if (*s == '/')
                                                                {
                                                                        ++s;

                                                                        if (*s == '>')
                                                                        {
                                                                                PUGI__POPNODE();
                                                                                s++;
                                                                                break;
                                                                        }
                                                                        else if (*s == 0 && endch == '>')
                                                                        {
                                                                                PUGI__POPNODE();
                                                                                break;
                                                                        }
                                                                        else PUGI__THROW_ERROR(status_bad_start_element, s);
                                                                }
                                                                else if (*s == '>')
                                                                {
                                                                        ++s;

                                                                        break;
                                                                }
                                                                else if (*s == 0 && endch == '>')
                                                                {
                                                                        break;
                                                                }
                                                                else PUGI__THROW_ERROR(status_bad_start_element, s);
                                                        }

                                                        // !!!
                                                }
                                                else if (ch == '/') // '<#.../'
                                                {
                                                        if (!PUGI__ENDSWITH(*s, '>')) PUGI__THROW_ERROR(status_bad_start_element, s);

                                                        PUGI__POPNODE(); // Pop.

                                                        s += (*s == '>');
                                                }
                                                else if (ch == 0)
                                                {
                                                        // we stepped over null terminator, backtrack & handle closing tag
                                                        --s;

                                                        if (endch != '>') PUGI__THROW_ERROR(status_bad_start_element, s);
                                                }
                                                else PUGI__THROW_ERROR(status_bad_start_element, s);
                                        }
                                        else if (*s == '/')
                                        {
                                                ++s;

                                                mark = s;

                                                char_t* name = cursor->name;
                                                if (!name) PUGI__THROW_ERROR(status_end_element_mismatch, mark);

                                                while (PUGI__IS_CHARTYPE(*s, ct_symbol))
                                                {
                                                        if (*s++ != *name++) PUGI__THROW_ERROR(status_end_element_mismatch, mark);
                                                }

                                                if (*name)
                                                {
                                                        if (*s == 0 && name[0] == endch && name[1] == 0) PUGI__THROW_ERROR(status_bad_end_element, s);
                                                        else PUGI__THROW_ERROR(status_end_element_mismatch, mark);
                                                }

                                                PUGI__POPNODE(); // Pop.

                                                PUGI__SKIPWS();

                                                if (*s == 0)
                                                {
                                                        if (endch != '>') PUGI__THROW_ERROR(status_bad_end_element, s);
                                                }
                                                else
                                                {
                                                        if (*s != '>') PUGI__THROW_ERROR(status_bad_end_element, s);
                                                        ++s;
                                                }
                                        }
                                        else if (*s == '?') // '<?...'
                                        {
                                                s = parse_question(s, cursor, optmsk, endch);
                                                if (!s) return s;

                                                assert(cursor);
                                                if (PUGI__NODETYPE(cursor) == node_declaration) goto LOC_ATTRIBUTES;
                                        }
                                        else if (*s == '!') // '<!...'
                                        {
                                                s = parse_exclamation(s, cursor, optmsk, endch);
                                                if (!s) return s;
                                        }
                                        else if (*s == 0 && endch == '?') PUGI__THROW_ERROR(status_bad_pi, s);
                                        else PUGI__THROW_ERROR(status_unrecognized_tag, s);
                                }
                                else
                                {
                                        mark = s; // Save this offset while searching for a terminator.

                                        PUGI__SKIPWS(); // Eat whitespace if no genuine PCDATA here.

                                        if (*s == '<' || !*s)
                                        {
                                                // We skipped some whitespace characters because otherwise we would take the tag branch instead of PCDATA one
                                                assert(mark != s);

                                                if (!PUGI__OPTSET(parse_ws_pcdata | parse_ws_pcdata_single) || PUGI__OPTSET(parse_trim_pcdata))
                                                {
                                                        continue;
                                                }
                                                else if (PUGI__OPTSET(parse_ws_pcdata_single))
                                                {
                                                        if (s[0] != '<' || s[1] != '/' || cursor->first_child) continue;
                                                }
                                        }

                                        if (!PUGI__OPTSET(parse_trim_pcdata))
                                                s = mark;

                                        if (cursor->parent || PUGI__OPTSET(parse_fragment))
                                        {
                                                if (PUGI__OPTSET(parse_embed_pcdata) && cursor->parent && !cursor->first_child && !cursor->value)
                                                {
                                                        cursor->value = s; // Save the offset.
                                                }
                                                else
                                                {
                                                        PUGI__PUSHNODE(node_pcdata); // Append a new node on the tree.

                                                        cursor->value = s; // Save the offset.

                                                        PUGI__POPNODE(); // Pop since this is a standalone.
                                                }

                                                s = strconv_pcdata(s);

                                                if (!*s) break;
                                        }
                                        else
                                        {
                                                PUGI__SCANFOR(*s == '<'); // '...<'
                                                if (!*s) break;

                                                ++s;
                                        }

                                        // We're after '<'
                                        goto LOC_TAG;
                                }
                        }

                        // check that last tag is closed
                        if (cursor != root) PUGI__THROW_ERROR(status_end_element_mismatch, s);

                        return s;
                }

        #ifdef PUGIXML_WCHAR_MODE
                static char_t* parse_skip_bom(char_t* s)
                {
                        unsigned int bom = 0xfeff;
                        return (s[0] == static_cast<wchar_t>(bom)) ? s + 1 : s;
                }
        #else
                static char_t* parse_skip_bom(char_t* s)
                {
                        return (s[0] == '\xef' && s[1] == '\xbb' && s[2] == '\xbf') ? s + 3 : s;
                }
        #endif

                static bool has_element_node_siblings(xml_node_struct* node)
                {
                        while (node)
                        {
                                if (PUGI__NODETYPE(node) == node_element) return true;

                                node = node->next_sibling;
                        }

                        return false;
                }

                static xml_parse_result parse(char_t* buffer, size_t length, xml_document_struct* xmldoc, xml_node_struct* root, unsigned int optmsk)
                {
                        // early-out for empty documents
                        if (length == 0)
                                return make_parse_result(PUGI__OPTSET(parse_fragment) ? status_ok : status_no_document_element);

                        // get last child of the root before parsing
                        xml_node_struct* last_root_child = root->first_child ? root->first_child->prev_sibling_c + 0 : 0;

                        // create parser on stack
                        xml_parser parser(static_cast<xml_allocator*>(xmldoc));

                        // save last character and make buffer zero-terminated (speeds up parsing)
                        char_t endch = buffer[length - 1];
                        buffer[length - 1] = 0;

                        // skip BOM to make sure it does not end up as part of parse output
                        char_t* buffer_data = parse_skip_bom(buffer);

                        // perform actual parsing
                        parser.parse_tree(buffer_data, root, optmsk, endch);

                        xml_parse_result result = make_parse_result(parser.error_status, parser.error_offset ? parser.error_offset - buffer : 0);
                        assert(result.offset >= 0 && static_cast<size_t>(result.offset) <= length);

                        if (result)
                        {
                                // since we removed last character, we have to handle the only possible false positive (stray <)
                                if (endch == '<')
                                        return make_parse_result(status_unrecognized_tag, length - 1);

                                // check if there are any element nodes parsed
                                xml_node_struct* first_root_child_parsed = last_root_child ? last_root_child->next_sibling + 0 : root->first_child+ 0;

                                if (!PUGI__OPTSET(parse_fragment) && !has_element_node_siblings(first_root_child_parsed))
                                        return make_parse_result(status_no_document_element, length - 1);
                        }
                        else
                        {
                                // roll back offset if it occurs on a null terminator in the source buffer
                                if (result.offset > 0 && static_cast<size_t>(result.offset) == length - 1 && endch == 0)
                                        result.offset--;
                        }

                        return result;
                }
        };

        // Output facilities
        PUGI__FN xml_encoding get_write_native_encoding()
        {
        #ifdef PUGIXML_WCHAR_MODE
                return get_wchar_encoding();
        #else
                return encoding_utf8;
        #endif
        }

        PUGI__FN xml_encoding get_write_encoding(xml_encoding encoding)
        {
                // replace wchar encoding with utf implementation
                if (encoding == encoding_wchar) return get_wchar_encoding();

                // replace utf16 encoding with utf16 with specific endianness
                if (encoding == encoding_utf16) return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                // replace utf32 encoding with utf32 with specific endianness
                if (encoding == encoding_utf32) return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                // only do autodetection if no explicit encoding is requested
                if (encoding != encoding_auto) return encoding;

                // assume utf8 encoding
                return encoding_utf8;
        }

        template <typename D, typename T> PUGI__FN size_t convert_buffer_output_generic(typename T::value_type dest, const char_t* data, size_t length, D, T)
        {
                PUGI__STATIC_ASSERT(sizeof(char_t) == sizeof(typename D::type));

                typename T::value_type end = D::process(reinterpret_cast<const typename D::type*>(data), length, dest, T());

                return static_cast<size_t>(end - dest) * sizeof(*dest);
        }

        template <typename D, typename T> PUGI__FN size_t convert_buffer_output_generic(typename T::value_type dest, const char_t* data, size_t length, D, T, bool opt_swap)
        {
                PUGI__STATIC_ASSERT(sizeof(char_t) == sizeof(typename D::type));

                typename T::value_type end = D::process(reinterpret_cast<const typename D::type*>(data), length, dest, T());

                if (opt_swap)
                {
                        for (typename T::value_type i = dest; i != end; ++i)
                                *i = endian_swap(*i);
                }

                return static_cast<size_t>(end - dest) * sizeof(*dest);
        }

#ifdef PUGIXML_WCHAR_MODE
        PUGI__FN size_t get_valid_length(const char_t* data, size_t length)
        {
                if (length < 1) return 0;

                // discard last character if it's the lead of a surrogate pair
                return (sizeof(wchar_t) == 2 && static_cast<unsigned int>(static_cast<uint16_t>(data[length - 1]) - 0xD800) < 0x400) ? length - 1 : length;
        }

        PUGI__FN size_t convert_buffer_output(char_t* r_char, uint8_t* r_u8, uint16_t* r_u16, uint32_t* r_u32, const char_t* data, size_t length, xml_encoding encoding)
        {
                // only endian-swapping is required
                if (need_endian_swap_utf(encoding, get_wchar_encoding()))
                {
                        convert_wchar_endian_swap(r_char, data, length);

                        return length * sizeof(char_t);
                }

                // convert to utf8
                if (encoding == encoding_utf8)
                        return convert_buffer_output_generic(r_u8, data, length, wchar_decoder(), utf8_writer());

                // convert to utf16
                if (encoding == encoding_utf16_be || encoding == encoding_utf16_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                        return convert_buffer_output_generic(r_u16, data, length, wchar_decoder(), utf16_writer(), native_encoding != encoding);
                }

                // convert to utf32
                if (encoding == encoding_utf32_be || encoding == encoding_utf32_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                        return convert_buffer_output_generic(r_u32, data, length, wchar_decoder(), utf32_writer(), native_encoding != encoding);
                }

                // convert to latin1
                if (encoding == encoding_latin1)
                        return convert_buffer_output_generic(r_u8, data, length, wchar_decoder(), latin1_writer());

                assert(false && "Invalid encoding");
                return 0;
        }
#else
        PUGI__FN size_t get_valid_length(const char_t* data, size_t length)
        {
                if (length < 5) return 0;

                for (size_t i = 1; i <= 4; ++i)
                {
                        uint8_t ch = static_cast<uint8_t>(data[length - i]);

                        // either a standalone character or a leading one
                        if ((ch & 0xc0) != 0x80) return length - i;
                }

                // there are four non-leading characters at the end, sequence tail is broken so might as well process the whole chunk
                return length;
        }

        PUGI__FN size_t convert_buffer_output(char_t* /* r_char */, uint8_t* r_u8, uint16_t* r_u16, uint32_t* r_u32, const char_t* data, size_t length, xml_encoding encoding)
        {
                if (encoding == encoding_utf16_be || encoding == encoding_utf16_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                        return convert_buffer_output_generic(r_u16, data, length, utf8_decoder(), utf16_writer(), native_encoding != encoding);
                }

                if (encoding == encoding_utf32_be || encoding == encoding_utf32_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                        return convert_buffer_output_generic(r_u32, data, length, utf8_decoder(), utf32_writer(), native_encoding != encoding);
                }

                if (encoding == encoding_latin1)
                        return convert_buffer_output_generic(r_u8, data, length, utf8_decoder(), latin1_writer());

                assert(false && "Invalid encoding");
                return 0;
        }
#endif

        class xml_buffered_writer
        {
                xml_buffered_writer(const xml_buffered_writer&);
                xml_buffered_writer& operator=(const xml_buffered_writer&);

        public:
                xml_buffered_writer(xml_writer& writer_, xml_encoding user_encoding): writer(writer_), bufsize(0), encoding(get_write_encoding(user_encoding))
                {
                        PUGI__STATIC_ASSERT(bufcapacity >= 8);
                }

                size_t flush()
                {
                        flush(buffer, bufsize);
                        bufsize = 0;
                        return 0;
                }

                void flush(const char_t* data, size_t size)
                {
                        if (size == 0) return;

                        // fast path, just write data
                        if (encoding == get_write_native_encoding())
                                writer.write(data, size * sizeof(char_t));
                        else
                        {
                                // convert chunk
                                size_t result = convert_buffer_output(scratch.data_char, scratch.data_u8, scratch.data_u16, scratch.data_u32, data, size, encoding);
                                assert(result <= sizeof(scratch));

                                // write data
                                writer.write(scratch.data_u8, result);
                        }
                }

                void write_direct(const char_t* data, size_t length)
                {
                        // flush the remaining buffer contents
                        flush();

                        // handle large chunks
                        if (length > bufcapacity)
                        {
                                if (encoding == get_write_native_encoding())
                                {
                                        // fast path, can just write data chunk
                                        writer.write(data, length * sizeof(char_t));
                                        return;
                                }

                                // need to convert in suitable chunks
                                while (length > bufcapacity)
                                {
                                        // get chunk size by selecting such number of characters that are guaranteed to fit into scratch buffer
                                        // and form a complete codepoint sequence (i.e. discard start of last codepoint if necessary)
                                        size_t chunk_size = get_valid_length(data, bufcapacity);
                                        assert(chunk_size);

                                        // convert chunk and write
                                        flush(data, chunk_size);

                                        // iterate
                                        data += chunk_size;
                                        length -= chunk_size;
                                }

                                // small tail is copied below
                                bufsize = 0;
                        }

                        memcpy(buffer + bufsize, data, length * sizeof(char_t));
                        bufsize += length;
                }

                void write_buffer(const char_t* data, size_t length)
                {
                        size_t offset = bufsize;

                        if (offset + length <= bufcapacity)
                        {
                                memcpy(buffer + offset, data, length * sizeof(char_t));
                                bufsize = offset + length;
                        }
                        else
                        {
                                write_direct(data, length);
                        }
                }

                void write_string(const char_t* data)
                {
                        // write the part of the string that fits in the buffer
                        size_t offset = bufsize;

                        while (*data && offset < bufcapacity)
                                buffer[offset++] = *data++;

                        // write the rest
                        if (offset < bufcapacity)
                        {
                                bufsize = offset;
                        }
                        else
                        {
                                // backtrack a bit if we have split the codepoint
                                size_t length = offset - bufsize;
                                size_t extra = length - get_valid_length(data - length, length);

                                bufsize = offset - extra;

                                write_direct(data - extra, strlength(data) + extra);
                        }
                }

                void write(char_t d0)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 1) offset = flush();

                        buffer[offset + 0] = d0;
                        bufsize = offset + 1;
                }

                void write(char_t d0, char_t d1)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 2) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        bufsize = offset + 2;
                }

                void write(char_t d0, char_t d1, char_t d2)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 3) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        buffer[offset + 2] = d2;
                        bufsize = offset + 3;
                }

                void write(char_t d0, char_t d1, char_t d2, char_t d3)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 4) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        buffer[offset + 2] = d2;
                        buffer[offset + 3] = d3;
                        bufsize = offset + 4;
                }

                void write(char_t d0, char_t d1, char_t d2, char_t d3, char_t d4)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 5) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        buffer[offset + 2] = d2;
                        buffer[offset + 3] = d3;
                        buffer[offset + 4] = d4;
                        bufsize = offset + 5;
                }

                void write(char_t d0, char_t d1, char_t d2, char_t d3, char_t d4, char_t d5)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 6) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        buffer[offset + 2] = d2;
                        buffer[offset + 3] = d3;
                        buffer[offset + 4] = d4;
                        buffer[offset + 5] = d5;
                        bufsize = offset + 6;
                }

                // utf8 maximum expansion: x4 (-> utf32)
                // utf16 maximum expansion: x2 (-> utf32)
                // utf32 maximum expansion: x1
                enum
                {
                        bufcapacitybytes =
                        #ifdef PUGIXML_MEMORY_OUTPUT_STACK
                                PUGIXML_MEMORY_OUTPUT_STACK
                        #else
                                10240
                        #endif
                        ,
                        bufcapacity = bufcapacitybytes / (sizeof(char_t) + 4)
                };

                char_t buffer[bufcapacity];

                union
                {
                        uint8_t data_u8[4 * bufcapacity];
                        uint16_t data_u16[2 * bufcapacity];
                        uint32_t data_u32[bufcapacity];
                        char_t data_char[bufcapacity];
                } scratch;

                xml_writer& writer;
                size_t bufsize;
                xml_encoding encoding;
        };

        PUGI__FN void text_output_escaped(xml_buffered_writer& writer, const char_t* s, chartypex_t type)
        {
                while (*s)
                {
                        const char_t* prev = s;

                        // While *s is a usual symbol
                        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPEX(ss, type));

                        writer.write_buffer(prev, static_cast<size_t>(s - prev));

                        switch (*s)
                        {
                                case 0: break;
                                case '&':
                                        writer.write('&', 'a', 'm', 'p', ';');
                                        ++s;
                                        break;
                                case '<':
                                        writer.write('&', 'l', 't', ';');
                                        ++s;
                                        break;
                                case '>':
                                        writer.write('&', 'g', 't', ';');
                                        ++s;
                                        break;
                                case '"':
                                        writer.write('&', 'q', 'u', 'o', 't', ';');
                                        ++s;
                                        break;
                                default: // s is not a usual symbol
                                {
                                        unsigned int ch = static_cast<unsigned int>(*s++);
                                        assert(ch < 32);

                                        writer.write('&', '#', static_cast<char_t>((ch / 10) + '0'), static_cast<char_t>((ch % 10) + '0'), ';');
                                }
                        }
                }
        }

        PUGI__FN void text_output(xml_buffered_writer& writer, const char_t* s, chartypex_t type, unsigned int flags)
        {
                if (flags & format_no_escapes)
                        writer.write_string(s);
                else
                        text_output_escaped(writer, s, type);
        }

        PUGI__FN void text_output_cdata(xml_buffered_writer& writer, const char_t* s)
        {
                do
                {
                        writer.write('<', '!', '[', 'C', 'D');
                        writer.write('A', 'T', 'A', '[');

                        const char_t* prev = s;

                        // look for ]]> sequence - we can't output it as is since it terminates CDATA
                        while (*s && !(s[0] == ']' && s[1] == ']' && s[2] == '>')) ++s;

                        // skip ]] if we stopped at ]]>, > will go to the next CDATA section
                        if (*s) s += 2;

                        writer.write_buffer(prev, static_cast<size_t>(s - prev));

                        writer.write(']', ']', '>');
                }
                while (*s);
        }

        PUGI__FN void text_output_indent(xml_buffered_writer& writer, const char_t* indent, size_t indent_length, unsigned int depth)
        {
                switch (indent_length)
                {
                case 1:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write(indent[0]);
                        break;
                }

                case 2:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write(indent[0], indent[1]);
                        break;
                }

                case 3:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write(indent[0], indent[1], indent[2]);
                        break;
                }

                case 4:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write(indent[0], indent[1], indent[2], indent[3]);
                        break;
                }

                default:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write_buffer(indent, indent_length);
                }
                }
        }

        PUGI__FN void node_output_comment(xml_buffered_writer& writer, const char_t* s)
        {
                writer.write('<', '!', '-', '-');

                while (*s)
                {
                        const char_t* prev = s;

                        // look for -\0 or -- sequence - we can't output it since -- is illegal in comment body
                        while (*s && !(s[0] == '-' && (s[1] == '-' || s[1] == 0))) ++s;

                        writer.write_buffer(prev, static_cast<size_t>(s - prev));

                        if (*s)
                        {
                                assert(*s == '-');

                                writer.write('-', ' ');
                                ++s;
                        }
                }

                writer.write('-', '-', '>');
        }

        PUGI__FN void node_output_pi_value(xml_buffered_writer& writer, const char_t* s)
        {
                while (*s)
                {
                        const char_t* prev = s;

                        // look for ?> sequence - we can't output it since ?> terminates PI
                        while (*s && !(s[0] == '?' && s[1] == '>')) ++s;

                        writer.write_buffer(prev, static_cast<size_t>(s - prev));

                        if (*s)
                        {
                                assert(s[0] == '?' && s[1] == '>');

                                writer.write('?', ' ', '>');
                                s += 2;
                        }
                }
        }

        PUGI__FN void node_output_attributes(xml_buffered_writer& writer, xml_node_struct* node, const char_t* indent, size_t indent_length, unsigned int flags, unsigned int depth)
        {
                const char_t* default_name = PUGIXML_TEXT(":anonymous");

                for (xml_attribute_struct* a = node->first_attribute; a; a = a->next_attribute)
                {
                        if ((flags & (format_indent_attributes | format_raw)) == format_indent_attributes)
                        {
                                writer.write('\n');

                                text_output_indent(writer, indent, indent_length, depth + 1);
                        }
                        else
                        {
                                writer.write(' ');
                        }

                        writer.write_string(a->name ? a->name + 0 : default_name);
                        writer.write('=', '"');

                        if (a->value)
                                text_output(writer, a->value, ctx_special_attr, flags);

                        writer.write('"');
                }
        }

        PUGI__FN bool node_output_start(xml_buffered_writer& writer, xml_node_struct* node, const char_t* indent, size_t indent_length, unsigned int flags, unsigned int depth)
        {
                const char_t* default_name = PUGIXML_TEXT(":anonymous");
                const char_t* name = node->name ? node->name + 0 : default_name;

                writer.write('<');
                writer.write_string(name);

                if (node->first_attribute)
                        node_output_attributes(writer, node, indent, indent_length, flags, depth);

                // element nodes can have value if parse_embed_pcdata was used
                if (!node->value)
                {
                        if (!node->first_child)
                        {
                                if (flags & format_no_empty_element_tags)
                                {
                                        writer.write('>', '<', '/');
                                        writer.write_string(name);
                                        writer.write('>');

                                        return false;
                                }
                                else
                                {
                                        if ((flags & format_raw) == 0)
                                                writer.write(' ');

                                        writer.write('/', '>');

                                        return false;
                                }
                        }
                        else
                        {
                                writer.write('>');

                                return true;
                        }
                }
                else
                {
                        writer.write('>');

                        text_output(writer, node->value, ctx_special_pcdata, flags);

                        if (!node->first_child)
                        {
                                writer.write('<', '/');
                                writer.write_string(name);
                                writer.write('>');

                                return false;
                        }
                        else
                        {
                                return true;
                        }
                }
        }

        PUGI__FN void node_output_end(xml_buffered_writer& writer, xml_node_struct* node)
        {
                const char_t* default_name = PUGIXML_TEXT(":anonymous");
                const char_t* name = node->name ? node->name + 0 : default_name;

                writer.write('<', '/');
                writer.write_string(name);
                writer.write('>');
        }

        PUGI__FN void node_output_simple(xml_buffered_writer& writer, xml_node_struct* node, unsigned int flags)
        {
                const char_t* default_name = PUGIXML_TEXT(":anonymous");

                switch (PUGI__NODETYPE(node))
                {
                        case node_pcdata:
                                text_output(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""), ctx_special_pcdata, flags);
                                break;

                        case node_cdata:
                                text_output_cdata(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""));
                                break;

                        case node_comment:
                                node_output_comment(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""));
                                break;

                        case node_pi:
                                writer.write('<', '?');
                                writer.write_string(node->name ? node->name + 0 : default_name);

                                if (node->value)
                                {
                                        writer.write(' ');
                                        node_output_pi_value(writer, node->value);
                                }

                                writer.write('?', '>');
                                break;

                        case node_declaration:
                                writer.write('<', '?');
                                writer.write_string(node->name ? node->name + 0 : default_name);
                                node_output_attributes(writer, node, PUGIXML_TEXT(""), 0, flags | format_raw, 0);
                                writer.write('?', '>');
                                break;

                        case node_doctype:
                                writer.write('<', '!', 'D', 'O', 'C');
                                writer.write('T', 'Y', 'P', 'E');

                                if (node->value)
                                {
                                        writer.write(' ');
                                        writer.write_string(node->value);
                                }

                                writer.write('>');
                                break;

                        default:
                                assert(false && "Invalid node type");
                }
        }

        enum indent_flags_t
        {
                indent_newline = 1,
                indent_indent = 2
        };

        PUGI__FN void node_output(xml_buffered_writer& writer, xml_node_struct* root, const char_t* indent, unsigned int flags, unsigned int depth)
        {
                size_t indent_length = ((flags & (format_indent | format_indent_attributes)) && (flags & format_raw) == 0) ? strlength(indent) : 0;
                unsigned int indent_flags = indent_indent;

                xml_node_struct* node = root;

                do
                {
                        assert(node);

                        // begin writing current node
                        if (PUGI__NODETYPE(node) == node_pcdata || PUGI__NODETYPE(node) == node_cdata)
                        {
                                node_output_simple(writer, node, flags);

                                indent_flags = 0;
                        }
                        else
                        {
                                if ((indent_flags & indent_newline) && (flags & format_raw) == 0)
                                        writer.write('\n');

                                if ((indent_flags & indent_indent) && indent_length)
                                        text_output_indent(writer, indent, indent_length, depth);

                                if (PUGI__NODETYPE(node) == node_element)
                                {
                                        indent_flags = indent_newline | indent_indent;

                                        if (node_output_start(writer, node, indent, indent_length, flags, depth))
                                        {
                                                // element nodes can have value if parse_embed_pcdata was used
                                                if (node->value)
                                                        indent_flags = 0;

                                                node = node->first_child;
                                                depth++;
                                                continue;
                                        }
                                }
                                else if (PUGI__NODETYPE(node) == node_document)
                                {
                                        indent_flags = indent_indent;

                                        if (node->first_child)
                                        {
                                                node = node->first_child;
                                                continue;
                                        }
                                }
                                else
                                {
                                        node_output_simple(writer, node, flags);

                                        indent_flags = indent_newline | indent_indent;
                                }
                        }

                        // continue to the next node
                        while (node != root)
                        {
                                if (node->next_sibling)
                                {
                                        node = node->next_sibling;
                                        break;
                                }

                                node = node->parent;

                                // write closing node
                                if (PUGI__NODETYPE(node) == node_element)
                                {
                                        depth--;

                                        if ((indent_flags & indent_newline) && (flags & format_raw) == 0)
                                                writer.write('\n');

                                        if ((indent_flags & indent_indent) && indent_length)
                                                text_output_indent(writer, indent, indent_length, depth);

                                        node_output_end(writer, node);

                                        indent_flags = indent_newline | indent_indent;
                                }
                        }
                }
                while (node != root);

                if ((indent_flags & indent_newline) && (flags & format_raw) == 0)
                        writer.write('\n');
        }

        PUGI__FN bool has_declaration(xml_node_struct* node)
        {
                for (xml_node_struct* child = node->first_child; child; child = child->next_sibling)
                {
                        xml_node_type type = PUGI__NODETYPE(child);

                        if (type == node_declaration) return true;
                        if (type == node_element) return false;
                }

                return false;
        }

        PUGI__FN bool is_attribute_of(xml_attribute_struct* attr, xml_node_struct* node)
        {
                for (xml_attribute_struct* a = node->first_attribute; a; a = a->next_attribute)
                        if (a == attr)
                                return true;

                return false;
        }

        PUGI__FN bool allow_insert_attribute(xml_node_type parent)
        {
                return parent == node_element || parent == node_declaration;
        }

        PUGI__FN bool allow_insert_child(xml_node_type parent, xml_node_type child)
        {
                if (parent != node_document && parent != node_element) return false;
                if (child == node_document || child == node_null) return false;
                if (parent != node_document && (child == node_declaration || child == node_doctype)) return false;

                return true;
        }

        PUGI__FN bool allow_move(xml_node parent, xml_node child)
        {
                // check that child can be a child of parent
                if (!allow_insert_child(parent.type(), child.type()))
                        return false;

                // check that node is not moved between documents
                if (parent.root() != child.root())
                        return false;

                // check that new parent is not in the child subtree
                xml_node cur = parent;

                while (cur)
                {
                        if (cur == child)
                                return false;

                        cur = cur.parent();
                }

                return true;
        }

        template <typename String, typename Header>
        PUGI__FN void node_copy_string(String& dest, Header& header, uintptr_t header_mask, char_t* source, Header& source_header, xml_allocator* alloc)
        {
                assert(!dest && (header & header_mask) == 0);

                if (source)
                {
                        if (alloc && (source_header & header_mask) == 0)
                        {
                                dest = source;

                                // since strcpy_insitu can reuse document buffer memory we need to mark both source and dest as shared
                                header |= xml_memory_page_contents_shared_mask;
                                source_header |= xml_memory_page_contents_shared_mask;
                        }
                        else
                                strcpy_insitu(dest, header, header_mask, source, strlength(source));
                }
        }

        PUGI__FN void node_copy_contents(xml_node_struct* dn, xml_node_struct* sn, xml_allocator* shared_alloc)
        {
                node_copy_string(dn->name, dn->header, xml_memory_page_name_allocated_mask, sn->name, sn->header, shared_alloc);
                node_copy_string(dn->value, dn->header, xml_memory_page_value_allocated_mask, sn->value, sn->header, shared_alloc);

                for (xml_attribute_struct* sa = sn->first_attribute; sa; sa = sa->next_attribute)
                {
                        xml_attribute_struct* da = append_new_attribute(dn, get_allocator(dn));

                        if (da)
                        {
                                node_copy_string(da->name, da->header, xml_memory_page_name_allocated_mask, sa->name, sa->header, shared_alloc);
                                node_copy_string(da->value, da->header, xml_memory_page_value_allocated_mask, sa->value, sa->header, shared_alloc);
                        }
                }
        }

        PUGI__FN void node_copy_tree(xml_node_struct* dn, xml_node_struct* sn)
        {
                xml_allocator& alloc = get_allocator(dn);
                xml_allocator* shared_alloc = (&alloc == &get_allocator(sn)) ? &alloc : 0;

                node_copy_contents(dn, sn, shared_alloc);

                xml_node_struct* dit = dn;
                xml_node_struct* sit = sn->first_child;

                while (sit && sit != sn)
                {
                        if (sit != dn)
                        {
                                xml_node_struct* copy = append_new_node(dit, alloc, PUGI__NODETYPE(sit));

                                if (copy)
                                {
                                        node_copy_contents(copy, sit, shared_alloc);

                                        if (sit->first_child)
                                        {
                                                dit = copy;
                                                sit = sit->first_child;
                                                continue;
                                        }
                                }
                        }

                        // continue to the next node
                        do
                        {
                                if (sit->next_sibling)
                                {
                                        sit = sit->next_sibling;
                                        break;
                                }

                                sit = sit->parent;
                                dit = dit->parent;
                        }
                        while (sit != sn);
                }
        }

        PUGI__FN void node_copy_attribute(xml_attribute_struct* da, xml_attribute_struct* sa)
        {
                xml_allocator& alloc = get_allocator(da);
                xml_allocator* shared_alloc = (&alloc == &get_allocator(sa)) ? &alloc : 0;

                node_copy_string(da->name, da->header, xml_memory_page_name_allocated_mask, sa->name, sa->header, shared_alloc);
                node_copy_string(da->value, da->header, xml_memory_page_value_allocated_mask, sa->value, sa->header, shared_alloc);
        }

        inline bool is_text_node(xml_node_struct* node)
        {
                xml_node_type type = PUGI__NODETYPE(node);

                return type == node_pcdata || type == node_cdata;
        }

        // get value with conversion functions
        template <typename U> U string_to_integer(const char_t* value, U minneg, U maxpos)
        {
                U result = 0;
                const char_t* s = value;

                while (PUGI__IS_CHARTYPE(*s, ct_space))
                        s++;

                bool negative = (*s == '-');

                s += (*s == '+' || *s == '-');

                bool overflow = false;

                if (s[0] == '0' && (s[1] | ' ') == 'x')
                {
                        s += 2;

                        // since overflow detection relies on length of the sequence skip leading zeros
                        while (*s == '0')
                                s++;

                        const char_t* start = s;

                        for (;;)
                        {
                                if (static_cast<unsigned>(*s - '0') < 10)
                                        result = result * 16 + (*s - '0');
                                else if (static_cast<unsigned>((*s | ' ') - 'a') < 6)
                                        result = result * 16 + ((*s | ' ') - 'a' + 10);
                                else
                                        break;

                                s++;
                        }

                        size_t digits = static_cast<size_t>(s - start);

                        overflow = digits > sizeof(U) * 2;
                }
                else
                {
                        // since overflow detection relies on length of the sequence skip leading zeros
                        while (*s == '0')
                                s++;

                        const char_t* start = s;

                        for (;;)
                        {
                                if (static_cast<unsigned>(*s - '0') < 10)
                                        result = result * 10 + (*s - '0');
                                else
                                        break;

                                s++;
                        }

                        size_t digits = static_cast<size_t>(s - start);

                        PUGI__STATIC_ASSERT(sizeof(U) == 8 || sizeof(U) == 4 || sizeof(U) == 2);

                        const size_t max_digits10 = sizeof(U) == 8 ? 20 : sizeof(U) == 4 ? 10 : 5;
                        const char_t max_lead = sizeof(U) == 8 ? '1' : sizeof(U) == 4 ? '4' : '6';
                        const size_t high_bit = sizeof(U) * 8 - 1;

                        overflow = digits >= max_digits10 && !(digits == max_digits10 && (*start < max_lead || (*start == max_lead && result >> high_bit)));
                }

                if (negative)
                        return (overflow || result > minneg) ? 0 - minneg : 0 - result;
                else
                        return (overflow || result > maxpos) ? maxpos : result;
        }

        PUGI__FN int get_value_int(const char_t* value)
        {
                return string_to_integer<unsigned int>(value, 0 - static_cast<unsigned int>(INT_MIN), INT_MAX);
        }

        PUGI__FN unsigned int get_value_uint(const char_t* value)
        {
                return string_to_integer<unsigned int>(value, 0, UINT_MAX);
        }

        PUGI__FN double get_value_double(const char_t* value)
        {
        #ifdef PUGIXML_WCHAR_MODE
                return wcstod(value, 0);
        #else
                return strtod(value, 0);
        #endif
        }

        PUGI__FN float get_value_float(const char_t* value)
        {
        #ifdef PUGIXML_WCHAR_MODE
                return static_cast<float>(wcstod(value, 0));
        #else
                return static_cast<float>(strtod(value, 0));
        #endif
        }

        PUGI__FN bool get_value_bool(const char_t* value)
        {
                // only look at first char
                char_t first = *value;

                // 1*, t* (true), T* (True), y* (yes), Y* (YES)
                return (first == '1' || first == 't' || first == 'T' || first == 'y' || first == 'Y');
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN long long get_value_llong(const char_t* value)
        {
                return string_to_integer<unsigned long long>(value, 0 - static_cast<unsigned long long>(LLONG_MIN), LLONG_MAX);
        }

        PUGI__FN unsigned long long get_value_ullong(const char_t* value)
        {
                return string_to_integer<unsigned long long>(value, 0, ULLONG_MAX);
        }
#endif

        template <typename U> PUGI__FN char_t* integer_to_string(char_t* begin, char_t* end, U value, bool negative)
        {
                char_t* result = end - 1;
                U rest = negative ? 0 - value : value;

                do
                {
                        *result-- = static_cast<char_t>('0' + (rest % 10));
                        rest /= 10;
                }
                while (rest);

                assert(result >= begin);
                (void)begin;

                *result = '-';

                return result + !negative;
        }

        // set value with conversion functions
        template <typename String, typename Header>
        PUGI__FN bool set_value_ascii(String& dest, Header& header, uintptr_t header_mask, char* buf)
        {
        #ifdef PUGIXML_WCHAR_MODE
                char_t wbuf[128];
                assert(strlen(buf) < sizeof(wbuf) / sizeof(wbuf[0]));

                size_t offset = 0;
                for (; buf[offset]; ++offset) wbuf[offset] = buf[offset];

                return strcpy_insitu(dest, header, header_mask, wbuf, offset);
        #else
                return strcpy_insitu(dest, header, header_mask, buf, strlen(buf));
        #endif
        }

        template <typename U, typename String, typename Header>
        PUGI__FN bool set_value_integer(String& dest, Header& header, uintptr_t header_mask, U value, bool negative)
        {
                char_t buf[64];
                char_t* end = buf + sizeof(buf) / sizeof(buf[0]);
                char_t* begin = integer_to_string(buf, end, value, negative);

                return strcpy_insitu(dest, header, header_mask, begin, end - begin);
        }

        template <typename String, typename Header>
        PUGI__FN bool set_value_convert(String& dest, Header& header, uintptr_t header_mask, float value)
        {
                char buf[128];
                sprintf(buf, "%.9g", value);

                return set_value_ascii(dest, header, header_mask, buf);
        }

        template <typename String, typename Header>
        PUGI__FN bool set_value_convert(String& dest, Header& header, uintptr_t header_mask, double value)
        {
                char buf[128];
                sprintf(buf, "%.17g", value);

                return set_value_ascii(dest, header, header_mask, buf);
        }

        template <typename String, typename Header>
        PUGI__FN bool set_value_bool(String& dest, Header& header, uintptr_t header_mask, bool value)
        {
                return strcpy_insitu(dest, header, header_mask, value ? PUGIXML_TEXT("true") : PUGIXML_TEXT("false"), value ? 4 : 5);
        }

        PUGI__FN xml_parse_result load_buffer_impl(xml_document_struct* doc, xml_node_struct* root, void* contents, size_t size, unsigned int options, xml_encoding encoding, bool is_mutable, bool own, char_t** out_buffer)
        {
                // check input buffer
                if (!contents && size) return make_parse_result(status_io_error);

                // get actual encoding
                xml_encoding buffer_encoding = impl::get_buffer_encoding(encoding, contents, size);

                // get private buffer
                char_t* buffer = 0;
                size_t length = 0;

                if (!impl::convert_buffer(buffer, length, buffer_encoding, contents, size, is_mutable)) return impl::make_parse_result(status_out_of_memory);

                // delete original buffer if we performed a conversion
                if (own && buffer != contents && contents) impl::xml_memory::deallocate(contents);

                // grab onto buffer if it's our buffer, user is responsible for deallocating contents himself
                if (own || buffer != contents) *out_buffer = buffer;

                // store buffer for offset_debug
                doc->buffer = buffer;

                // parse
                xml_parse_result res = impl::xml_parser::parse(buffer, length, doc, root, options);

                // remember encoding
                res.encoding = buffer_encoding;

                return res;
        }

        // we need to get length of entire file to load it in memory; the only (relatively) sane way to do it is via seek/tell trick
        PUGI__FN xml_parse_status get_file_size(FILE* file, size_t& out_result)
        {
        #if defined(PUGI__MSVC_CRT_VERSION) && PUGI__MSVC_CRT_VERSION >= 1400 && !defined(_WIN32_WCE)
                // there are 64-bit versions of fseek/ftell, let's use them
                typedef __int64 length_type;

                _fseeki64(file, 0, SEEK_END);
                length_type length = _ftelli64(file);
                _fseeki64(file, 0, SEEK_SET);
        #elif defined(__MINGW32__) && !defined(__NO_MINGW_LFS) && (!defined(__STRICT_ANSI__) || defined(__MINGW64_VERSION_MAJOR))
                // there are 64-bit versions of fseek/ftell, let's use them
                typedef off64_t length_type;

                fseeko64(file, 0, SEEK_END);
                length_type length = ftello64(file);
                fseeko64(file, 0, SEEK_SET);
        #else
                // if this is a 32-bit OS, long is enough; if this is a unix system, long is 64-bit, which is enough; otherwise we can't do anything anyway.
                typedef long length_type;

                fseek(file, 0, SEEK_END);
                length_type length = ftell(file);
                fseek(file, 0, SEEK_SET);
        #endif

                // check for I/O errors
                if (length < 0) return status_io_error;

                // check for overflow
                size_t result = static_cast<size_t>(length);

                if (static_cast<length_type>(result) != length) return status_out_of_memory;

                // finalize
                out_result = result;

                return status_ok;
        }

        // This function assumes that buffer has extra sizeof(char_t) writable bytes after size
        PUGI__FN size_t zero_terminate_buffer(void* buffer, size_t size, xml_encoding encoding)
        {
                // We only need to zero-terminate if encoding conversion does not do it for us
        #ifdef PUGIXML_WCHAR_MODE
                xml_encoding wchar_encoding = get_wchar_encoding();

                if (encoding == wchar_encoding || need_endian_swap_utf(encoding, wchar_encoding))
                {
                        size_t length = size / sizeof(char_t);

                        static_cast<char_t*>(buffer)[length] = 0;
                        return (length + 1) * sizeof(char_t);
                }
        #else
                if (encoding == encoding_utf8)
                {
                        static_cast<char*>(buffer)[size] = 0;
                        return size + 1;
                }
        #endif

                return size;
        }

        PUGI__FN xml_parse_result load_file_impl(xml_document_struct* doc, FILE* file, unsigned int options, xml_encoding encoding, char_t** out_buffer)
        {
                if (!file) return make_parse_result(status_file_not_found);

                // get file size (can result in I/O errors)
                size_t size = 0;
                xml_parse_status size_status = get_file_size(file, size);
                if (size_status != status_ok) return make_parse_result(size_status);

                size_t max_suffix_size = sizeof(char_t);

                // allocate buffer for the whole file
                char* contents = static_cast<char*>(xml_memory::allocate(size + max_suffix_size));
                if (!contents) return make_parse_result(status_out_of_memory);

                // read file in memory
                size_t read_size = fread(contents, 1, size, file);

                if (read_size != size)
                {
                        xml_memory::deallocate(contents);
                        return make_parse_result(status_io_error);
                }

                xml_encoding real_encoding = get_buffer_encoding(encoding, contents, size);

                return load_buffer_impl(doc, doc, contents, zero_terminate_buffer(contents, size, real_encoding), options, real_encoding, true, true, out_buffer);
        }

        PUGI__FN void close_file(FILE* file)
        {
                fclose(file);
        }

#ifndef PUGIXML_NO_STL
        template <typename T> struct xml_stream_chunk
        {
                static xml_stream_chunk* create()
                {
                        void* memory = xml_memory::allocate(sizeof(xml_stream_chunk));
                        if (!memory) return 0;

                        return new (memory) xml_stream_chunk();
                }

                static void destroy(xml_stream_chunk* chunk)
                {
                        // free chunk chain
                        while (chunk)
                        {
                                xml_stream_chunk* next_ = chunk->next;

                                xml_memory::deallocate(chunk);

                                chunk = next_;
                        }
                }

                xml_stream_chunk(): next(0), size(0)
                {
                }

                xml_stream_chunk* next;
                size_t size;

                T data[xml_memory_page_size / sizeof(T)];
        };

        template <typename T> PUGI__FN xml_parse_status load_stream_data_noseek(std::basic_istream<T>& stream, void** out_buffer, size_t* out_size)
        {
                auto_deleter<xml_stream_chunk<T> > chunks(0, xml_stream_chunk<T>::destroy);

                // read file to a chunk list
                size_t total = 0;
                xml_stream_chunk<T>* last = 0;

                while (!stream.eof())
                {
                        // allocate new chunk
                        xml_stream_chunk<T>* chunk = xml_stream_chunk<T>::create();
                        if (!chunk) return status_out_of_memory;

                        // append chunk to list
                        if (last) last = last->next = chunk;
                        else chunks.data = last = chunk;

                        // read data to chunk
                        stream.read(chunk->data, static_cast<std::streamsize>(sizeof(chunk->data) / sizeof(T)));
                        chunk->size = static_cast<size_t>(stream.gcount()) * sizeof(T);

                        // read may set failbit | eofbit in case gcount() is less than read length, so check for other I/O errors
                        if (stream.bad() || (!stream.eof() && stream.fail())) return status_io_error;

                        // guard against huge files (chunk size is small enough to make this overflow check work)
                        if (total + chunk->size < total) return status_out_of_memory;
                        total += chunk->size;
                }

                size_t max_suffix_size = sizeof(char_t);

                // copy chunk list to a contiguous buffer
                char* buffer = static_cast<char*>(xml_memory::allocate(total + max_suffix_size));
                if (!buffer) return status_out_of_memory;

                char* write = buffer;

                for (xml_stream_chunk<T>* chunk = chunks.data; chunk; chunk = chunk->next)
                {
                        assert(write + chunk->size <= buffer + total);
                        memcpy(write, chunk->data, chunk->size);
                        write += chunk->size;
                }

                assert(write == buffer + total);

                // return buffer
                *out_buffer = buffer;
                *out_size = total;

                return status_ok;
        }

        template <typename T> PUGI__FN xml_parse_status load_stream_data_seek(std::basic_istream<T>& stream, void** out_buffer, size_t* out_size)
        {
                // get length of remaining data in stream
                typename std::basic_istream<T>::pos_type pos = stream.tellg();
                stream.seekg(0, std::ios::end);
                std::streamoff length = stream.tellg() - pos;
                stream.seekg(pos);

                if (stream.fail() || pos < 0) return status_io_error;

                // guard against huge files
                size_t read_length = static_cast<size_t>(length);

                if (static_cast<std::streamsize>(read_length) != length || length < 0) return status_out_of_memory;

                size_t max_suffix_size = sizeof(char_t);

                // read stream data into memory (guard against stream exceptions with buffer holder)
                auto_deleter<void> buffer(xml_memory::allocate(read_length * sizeof(T) + max_suffix_size), xml_memory::deallocate);
                if (!buffer.data) return status_out_of_memory;

                stream.read(static_cast<T*>(buffer.data), static_cast<std::streamsize>(read_length));

                // read may set failbit | eofbit in case gcount() is less than read_length (i.e. line ending conversion), so check for other I/O errors
                if (stream.bad() || (!stream.eof() && stream.fail())) return status_io_error;

                // return buffer
                size_t actual_length = static_cast<size_t>(stream.gcount());
                assert(actual_length <= read_length);

                *out_buffer = buffer.release();
                *out_size = actual_length * sizeof(T);

                return status_ok;
        }

        template <typename T> PUGI__FN xml_parse_result load_stream_impl(xml_document_struct* doc, std::basic_istream<T>& stream, unsigned int options, xml_encoding encoding, char_t** out_buffer)
        {
                void* buffer = 0;
                size_t size = 0;
                xml_parse_status status = status_ok;

                // if stream has an error bit set, bail out (otherwise tellg() can fail and we'll clear error bits)
                if (stream.fail()) return make_parse_result(status_io_error);

                // load stream to memory (using seek-based implementation if possible, since it's faster and takes less memory)
                if (stream.tellg() < 0)
                {
                        stream.clear(); // clear error flags that could be set by a failing tellg
                        status = load_stream_data_noseek(stream, &buffer, &size);
                }
                else
                        status = load_stream_data_seek(stream, &buffer, &size);

                if (status != status_ok) return make_parse_result(status);

                xml_encoding real_encoding = get_buffer_encoding(encoding, buffer, size);

                return load_buffer_impl(doc, doc, buffer, zero_terminate_buffer(buffer, size, real_encoding), options, real_encoding, true, true, out_buffer);
        }
#endif

#if defined(PUGI__MSVC_CRT_VERSION) || defined(__BORLANDC__) || (defined(__MINGW32__) && (!defined(__STRICT_ANSI__) || defined(__MINGW64_VERSION_MAJOR)))
        PUGI__FN FILE* open_file_wide(const wchar_t* path, const wchar_t* mode)
        {
                return _wfopen(path, mode);
        }
#else
        PUGI__FN char* convert_path_heap(const wchar_t* str)
        {
                assert(str);

                // first pass: get length in utf8 characters
                size_t length = strlength_wide(str);
                size_t size = as_utf8_begin(str, length);

                // allocate resulting string
                char* result = static_cast<char*>(xml_memory::allocate(size + 1));
                if (!result) return 0;

                // second pass: convert to utf8
                as_utf8_end(result, size, str, length);

                // zero-terminate
                result[size] = 0;

                return result;
        }

        PUGI__FN FILE* open_file_wide(const wchar_t* path, const wchar_t* mode)
        {
                // there is no standard function to open wide paths, so our best bet is to try utf8 path
                char* path_utf8 = convert_path_heap(path);
                if (!path_utf8) return 0;

                // convert mode to ASCII (we mirror _wfopen interface)
                char mode_ascii[4] = {0};
                for (size_t i = 0; mode[i]; ++i) mode_ascii[i] = static_cast<char>(mode[i]);

                // try to open the utf8 path
                FILE* result = fopen(path_utf8, mode_ascii);

                // free dummy buffer
                xml_memory::deallocate(path_utf8);

                return result;
        }
#endif

        PUGI__FN bool save_file_impl(const xml_document& doc, FILE* file, const char_t* indent, unsigned int flags, xml_encoding encoding)
        {
                if (!file) return false;

                xml_writer_file writer(file);
                doc.save(writer, indent, flags, encoding);

                return ferror(file) == 0;
        }

        struct name_null_sentry
        {
                xml_node_struct* node;
                char_t* name;

                name_null_sentry(xml_node_struct* node_): node(node_), name(node_->name)
                {
                        node->name = 0;
                }

                ~name_null_sentry()
                {
                        node->name = name;
                }
        };
PUGI__NS_END

OIIO_NAMESPACE_BEGIN namespace pugi
{
        PUGI__FN xml_writer_file::xml_writer_file(void* file_): file(file_)
        {
        }

        PUGI__FN void xml_writer_file::write(const void* data, size_t size)
        {
                size_t result = fwrite(data, 1, size, static_cast<FILE*>(file));
                (void)!result; // unfortunately we can't do proper error handling here
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN xml_writer_stream::xml_writer_stream(std::basic_ostream<char, std::char_traits<char> >& stream): narrow_stream(&stream), wide_stream(0)
        {
        }

        PUGI__FN xml_writer_stream::xml_writer_stream(std::basic_ostream<wchar_t, std::char_traits<wchar_t> >& stream): narrow_stream(0), wide_stream(&stream)
        {
        }

        PUGI__FN void xml_writer_stream::write(const void* data, size_t size)
        {
                if (narrow_stream)
                {
                        assert(!wide_stream);
                        narrow_stream->write(reinterpret_cast<const char*>(data), static_cast<std::streamsize>(size));
                }
                else
                {
                        assert(wide_stream);
                        assert(size % sizeof(wchar_t) == 0);

                        wide_stream->write(reinterpret_cast<const wchar_t*>(data), static_cast<std::streamsize>(size / sizeof(wchar_t)));
                }
        }
#endif

        PUGI__FN xml_tree_walker::xml_tree_walker(): _depth(0)
        {
        }

        PUGI__FN xml_tree_walker::~xml_tree_walker()
        {
        }

        PUGI__FN int xml_tree_walker::depth() const
        {
                return _depth;
        }

        PUGI__FN bool xml_tree_walker::begin(xml_node&)
        {
                return true;
        }

        PUGI__FN bool xml_tree_walker::end(xml_node&)
        {
                return true;
        }

        PUGI__FN xml_attribute::xml_attribute(): _attr(0)
        {
        }

        PUGI__FN xml_attribute::xml_attribute(xml_attribute_struct* attr): _attr(attr)
        {
        }

        PUGI__FN static void unspecified_bool_xml_attribute(xml_attribute***)
        {
        }

        PUGI__FN xml_attribute::operator xml_attribute::unspecified_bool_type() const
        {
                return _attr ? unspecified_bool_xml_attribute : 0;
        }

        PUGI__FN bool xml_attribute::operator!() const
        {
                return !_attr;
        }

        PUGI__FN bool xml_attribute::operator==(const xml_attribute& r) const
        {
                return (_attr == r._attr);
        }

        PUGI__FN bool xml_attribute::operator!=(const xml_attribute& r) const
        {
                return (_attr != r._attr);
        }

        PUGI__FN bool xml_attribute::operator<(const xml_attribute& r) const
        {
                return (_attr < r._attr);
        }

        PUGI__FN bool xml_attribute::operator>(const xml_attribute& r) const
        {
                return (_attr > r._attr);
        }

        PUGI__FN bool xml_attribute::operator<=(const xml_attribute& r) const
        {
                return (_attr <= r._attr);
        }

        PUGI__FN bool xml_attribute::operator>=(const xml_attribute& r) const
        {
                return (_attr >= r._attr);
        }

        PUGI__FN xml_attribute xml_attribute::next_attribute() const
        {
                return _attr ? xml_attribute(_attr->next_attribute) : xml_attribute();
        }

        PUGI__FN xml_attribute xml_attribute::previous_attribute() const
        {
                return _attr && _attr->prev_attribute_c->next_attribute ? xml_attribute(_attr->prev_attribute_c) : xml_attribute();
        }

        PUGI__FN const char_t* xml_attribute::as_string(const char_t* def) const
        {
                return (_attr && _attr->value) ? _attr->value + 0 : def;
        }

        PUGI__FN int xml_attribute::as_int(int def) const
        {
                return (_attr && _attr->value) ? impl::get_value_int(_attr->value) : def;
        }

        PUGI__FN unsigned int xml_attribute::as_uint(unsigned int def) const
        {
                return (_attr && _attr->value) ? impl::get_value_uint(_attr->value) : def;
        }

        PUGI__FN double xml_attribute::as_double(double def) const
        {
                return (_attr && _attr->value) ? impl::get_value_double(_attr->value) : def;
        }

        PUGI__FN float xml_attribute::as_float(float def) const
        {
                return (_attr && _attr->value) ? impl::get_value_float(_attr->value) : def;
        }

        PUGI__FN bool xml_attribute::as_bool(bool def) const
        {
                return (_attr && _attr->value) ? impl::get_value_bool(_attr->value) : def;
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN long long xml_attribute::as_llong(long long def) const
        {
                return (_attr && _attr->value) ? impl::get_value_llong(_attr->value) : def;
        }

        PUGI__FN unsigned long long xml_attribute::as_ullong(unsigned long long def) const
        {
                return (_attr && _attr->value) ? impl::get_value_ullong(_attr->value) : def;
        }
#endif

        PUGI__FN bool xml_attribute::empty() const
        {
                return !_attr;
        }

        PUGI__FN const char_t* xml_attribute::name() const
        {
                return (_attr && _attr->name) ? _attr->name + 0 : PUGIXML_TEXT("");
        }

        PUGI__FN const char_t* xml_attribute::value() const
        {
                return (_attr && _attr->value) ? _attr->value + 0 : PUGIXML_TEXT("");
        }

        PUGI__FN size_t xml_attribute::hash_value() const
        {
                return static_cast<size_t>(reinterpret_cast<uintptr_t>(_attr) / sizeof(xml_attribute_struct));
        }

        PUGI__FN xml_attribute_struct* xml_attribute::internal_object() const
        {
                return _attr;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(const char_t* rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(int rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(unsigned int rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(long rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(unsigned long rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(double rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(float rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(bool rhs)
        {
                set_value(rhs);
                return *this;
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN xml_attribute& xml_attribute::operator=(long long rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(unsigned long long rhs)
        {
                set_value(rhs);
                return *this;
        }
#endif

        PUGI__FN bool xml_attribute::set_name(const char_t* rhs)
        {
                if (!_attr) return false;

                return impl::strcpy_insitu(_attr->name, _attr->header, impl::xml_memory_page_name_allocated_mask, rhs, impl::strlength(rhs));
        }

        PUGI__FN bool xml_attribute::set_value(const char_t* rhs)
        {
                if (!_attr) return false;

                return impl::strcpy_insitu(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, impl::strlength(rhs));
        }

        PUGI__FN bool xml_attribute::set_value(int rhs)
        {
                if (!_attr) return false;

                return impl::set_value_integer<unsigned int>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0);
        }

        PUGI__FN bool xml_attribute::set_value(unsigned int rhs)
        {
                if (!_attr) return false;