/*!
* \file void_t.h
* \brief Template meta-programming helpers
*
* Copyright (C) 2018 Christos Choutouridis
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3
* 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see .
*/
#ifndef __utl_meta_void_t_h__
#define __utl_meta_void_t_h__
#include
//! \ingroup meta
//! \defgroup void_t
//! A void_t implementation for utl
//! @{
namespace utl {
/*!
* Utility meta-function that maps a sequence of any types to the type void
* \note The idea is:
* template
* using void_t = void;
*
* Until CWG 1558 (a C++14 defect), unused parameters in alias templates were not
* guaranteed to ensure SFINAE and could be ignored, so earlier compilers require
* a more complex definition of void_t, such as the following implementation
* https://en.cppreference.com
*/
template
struct void_impl {
typedef void type;
};
//! The actual void_t type alias
template
using void_t = typename void_impl<_Ts...>::type;
}
//! @}
#endif /* __utl_meta_void_t_h__ */