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- /*!
- * \file useif.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 <http://www.gnu.org/licenses/>.
- */
- #ifndef __utl_meta_useif_h__
- #define __utl_meta_useif_h__
-
- #include <utl/core/impl.h>
- #include <utl/meta/operations.h>
- #include <utl/meta/sfinae.h>
-
- /*!
- * \ingroup meta
- * \defgroup sfinae
- * conditional use support header. This is a SFINAE wrapper
- */
- //! @{
- namespace utl {
- namespace meta {
-
- //! If same type resolves to _Ret, else SFINAE
- template <typename _T1, typename _T2, typename _Ret =_T1>
- using use_if_same_t = enable_if_t<
- same_<_T1, _T2>::value, _Ret
- >;
- //! If not same type resolves to _Ret, else SFINAE
- template <typename _T1, typename _T2, typename _Ret =_T1>
- using use_if_not_same_t = enable_if_t<
- !same_<_T1, _T2>::value, _Ret
- >;
- //! If any type (_T1 or _T2) type resolves to _Ret, else to SFINAE
- template <typename T1, typename... Ts>
- using use_if_any_t = enable_if_t<
- or_<T1, Ts...>::value, T1
- >;
-
- //! If both type (_T1 and _T2) type resolves to _Ret, else to SFINAE
- template <typename T1, typename... Ts>
- using use_if_all_t = enable_if_t<
- and_<T1, Ts...>::value, T1
- >;
-
- }}
-
- //! @}
-
- #endif /* __utl_meta_useif_h__ */
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