PY_CallMethod.h

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * COMMENTS:
 *      This file contains functionality to call methods on python objects,
 *      specifically when arguments need to be passed to the call.
 *
 *      You should only need to include this file in .C files, not in .h files.
 */

#ifndef __PY_CallMethod_h__
#define __PY_CallMethod_h__

#include "PY_CPythonAPI.h"
#include "PY_AutoObject.h"
#include "PY_InterpreterAutoLock.h"
#include "PY_Python.h"
#include "PY_Result.h"

/// Given an (opaque) Python object, call one of its methods
/// and return its result, converting to the desired type.
///
/// This is identical to PYcallMethodOnPythonObject in PY_Python.h
/// except that it uses a template parameter pack to forward arguments
/// to the function call.
/// 
/// NOTE: there is an issue with clang (pre-v11) that means you can *not*
///       make any of the arguments have default values
///       (see https://bugs.llvm.org/show_bug.cgi?id=23029#c3) 
template <typename ...Args>
PY_Result PYcallMethodOnPythonObjectWithArgs(
        void *opaque_python_object, const char *method_name,
        PY_Result::Type desired_result_type,
        const char *format, Args&&... args)
{
    PY_InterpreterAutoLock python_lock;
    UT_ASSERT(opaque_python_object);
    PY_PyObject *python_object = (PY_PyObject *)opaque_python_object;
    PY_AutoObject result_object = PY_PyObject_CallMethod(
            python_object, method_name, format, std::forward<Args>(args)...);
    if (!result_object)
        return PYextractPythonException();
    return PYextractResultFromPythonObject(result_object, desired_result_type);
}

#endif