63 lines
1.9 KiB
C++
63 lines
1.9 KiB
C++
/*!
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* \file useif.h
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* \brief Template meta-programming SFINAE helpers
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*
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* Copyright (C) 2018 Christos Choutouridis
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation, either version 3
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __utl_meta_useif_h__
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#define __utl_meta_useif_h__
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#include <utl/core/impl.h>
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#include <utl/meta/operations.h>
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#include <utl/meta/sfinae.h>
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/*!
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* \ingroup meta
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* \defgroup sfinae
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* conditional use support header. This is a SFINAE wrapper
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*/
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//! @{
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namespace utl {
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namespace meta {
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//! If same type resolves to _Ret, else SFINAE
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template <typename _T1, typename _T2, typename _Ret =_T1>
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using use_if_same_t = enable_if_t<
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same_<_T1, _T2>::value, _Ret
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>;
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//! If not same type resolves to _Ret, else SFINAE
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template <typename _T1, typename _T2, typename _Ret =_T1>
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using use_if_not_same_t = enable_if_t<
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!same_<_T1, _T2>::value, _Ret
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>;
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//! If any type (_T1 or _T2) type resolves to _Ret, else to SFINAE
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template <typename T1, typename... Ts>
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using use_if_any_t = enable_if_t<
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or_<T1, Ts...>::value, T1
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>;
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//! If both type (_T1 and _T2) type resolves to _Ret, else to SFINAE
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template <typename T1, typename... Ts>
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using use_if_all_t = enable_if_t<
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and_<T1, Ts...>::value, T1
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>;
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}}
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//! @}
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#endif /* __utl_meta_useif_h__ */
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