valentina_old/src/libs/vmisc/backport/qoverload.h
Roman Telezhynskyi 5c8c940f32 Refactoring. Backport QOverload template.
--HG--
branch : develop
2018-01-12 15:25:20 +02:00

87 lines
3.1 KiB
C++

/************************************************************************
**
** @file qoverload.h
** @author Roman Telezhynskyi <dismine(at)gmail.com>
** @date 12 1, 2018
**
** @brief
** @copyright
** This source code is part of the Valentina project, a pattern making
** program, whose allow create and modeling patterns of clothing.
** Copyright (C) 2018 Valentina project
** <https://bitbucket.org/dismine/valentina> All Rights Reserved.
**
** Valentina is free software: you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation, either version 3 of the License, or
** (at your option) any later version.
**
** Valentina is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with Valentina. If not, see <http://www.gnu.org/licenses/>.
**
*************************************************************************/
#ifndef QOVERLOAD_H
#define QOVERLOAD_H
#include <QtGlobal>
#if QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
#if defined(Q_COMPILER_VARIADIC_TEMPLATES)
template <typename... Args>
struct QNonConstOverload
{
template <typename R, typename T>
Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...)) const Q_DECL_NOTHROW -> decltype(ptr)
{ return ptr; }
template <typename R, typename T>
static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...)) Q_DECL_NOTHROW -> decltype(ptr)
{ return ptr; }
};
template <typename... Args>
struct QConstOverload
{
template <typename R, typename T>
Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...) const) const Q_DECL_NOTHROW -> decltype(ptr)
{ return ptr; }
template <typename R, typename T>
static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...) const) Q_DECL_NOTHROW -> decltype(ptr)
{ return ptr; }
};
template <typename... Args>
struct QOverload : QConstOverload<Args...>, QNonConstOverload<Args...>
{
using QConstOverload<Args...>::of;
using QConstOverload<Args...>::operator();
using QNonConstOverload<Args...>::of;
using QNonConstOverload<Args...>::operator();
template <typename R>
Q_DECL_CONSTEXPR auto operator()(R (*ptr)(Args...)) const Q_DECL_NOTHROW -> decltype(ptr)
{ return ptr; }
template <typename R>
static Q_DECL_CONSTEXPR auto of(R (*ptr)(Args...)) Q_DECL_NOTHROW -> decltype(ptr)
{ return ptr; }
};
#if defined(__cpp_variable_templates) && __cpp_variable_templates >= 201304 // C++14
template <typename... Args> Q_CONSTEXPR Q_DECL_UNUSED QOverload<Args...> qOverload = {};
template <typename... Args> Q_CONSTEXPR Q_DECL_UNUSED QConstOverload<Args...> qConstOverload = {};
template <typename... Args> Q_CONSTEXPR Q_DECL_UNUSED QNonConstOverload<Args...> qNonConstOverload = {};
#endif
#endif // Q_COMPILER_VARIADIC_TEMPLATES
#endif // QT_VERSION < QT_VERSION_CHECK(5, 7, 0)
#endif // QOVERLOAD_H