/*!
* \file use.h
* \brief Template meta-programming SFINAE 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_use_h__
#define __utl_meta_use_h__
#include
#include
/*!
* \ingroup meta
* \defgroup use
* conditional use support header. This is a SFINAE helper
*/
//! @{
namespace utl {
//! If same type resolves to _Ret, else to SFINAE
//! @{
template
struct use_if_same_ {
using type = enable_if_t <
same_<_Tp1, _Tp2>::value,
_Ret
>;
};
template
using use_if_same_t = typename use_if_same_<_Tp1, _Tp2, _Ret>::type;
//! @}
//! If same type resolves to SFINAE, else to _Ret
//! @{
template
struct discard_if_same_ {
using type = enable_if_t <
!same_<_Tp1, _Tp2>::value,
_Ret
>;
};
template
using discard_if_same_t = typename discard_if_same_<_Tp1, _Tp2, _Ret>::type;
//! @}
}
//! @}
#endif /* __utl_meta_use_h__ */