/*!
* \file sfinae.h
* \brief Template meta-programming SFINAE helpers
*
* Copyright (C) 2018-2019 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_sfinae_h__
#define __utl_meta_sfinae_h__
#include
#include
/*!
* \ingroup meta
* \defgroup sfinae
* conditional use support header.
*/
//! @{
namespace utl {
namespace meta {
//! Tool to enable a partial specialization only if a boolean condition is true.
//! @{
namespace detail {
// template
// struct dev_null { using type = dev_null; }; //< Same as typelist
template struct when_ { };
template <> struct when_ { using type = void; };
}
//! Well formed only if \p If is true
template
using when = eval< detail::when_ >;
// //! Well formed only if all of \p Ifs are \c true
// template
// using when_all = detail::dev_null<
// when...
// >;
//! @}
//! enable_if
//! @{
//! enable_if, imported from stl
template using enable_if = std::enable_if;
//! alias template for enable_if
template using enable_if_t = eval< enable_if >;
//! @}
}}
//! @}
#endif /* __utl_meta_sfinae_h__ */