kicad/include/make_unique.h

89 lines
2.9 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2017 KiCad Developers, see AUTHORS.txt for contributors.
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/**
* @file make_unique.h
* @brief Implementation of std::make_unique for pre C++14 compilation
* environments
*/
#ifndef MAKE_UNIQUE_H
#define MAKE_UNIQUE_H
// Define std::make_unique if the compiler is C++11, but not C++14
// (which provides this itself)
// When C++14 support is a KiCad pre-requisite, this entire file
// can be removed.
#if __cplusplus == 201103L
#include <cstddef>
#include <memory>
#include <type_traits>
#include <utility>
// It's a bit naughty to add things to std::, but the point is to
// "polyfill" this function in only if std:: doesn't have it
//
// This implementation is the one proposed by Stephan T. Lavavej
// in N3656: https://isocpp.org/files/papers/N3656.txt
// This is more or less exactly how it is implemented in GCC (e.g. 6.3.1)
// when C++14 is enabled.
namespace std
{
template<class T> struct _Unique_if {
typedef unique_ptr<T> _Single_object;
};
template<class T> struct _Unique_if<T[]> {
typedef unique_ptr<T[]> _Unknown_bound;
};
template<class T, size_t N> struct _Unique_if<T[N]> {
typedef void _Known_bound;
};
/// std::make_unique for single objects
template<class T, class... Args>
typename _Unique_if<T>::_Single_object
make_unique(Args&&... args) {
return unique_ptr<T>(new T(std::forward<Args>(args)...));
}
/// std::make_unique for arrays of unknown bound
template<class T>
typename _Unique_if<T>::_Unknown_bound
make_unique(size_t n) {
typedef typename remove_extent<T>::type U;
return unique_ptr<T>(new U[n]());
}
/// Disable std::make_unique for arrays of known bound
template<class T, class... Args>
typename _Unique_if<T>::_Known_bound
make_unique(Args&&...) = delete;
}
#endif // __cplusplus == 201103L
#endif // WXSTRUCT_H_