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Diffstat (limited to 'src/utilities/meta.h')
-rw-r--r-- | src/utilities/meta.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/utilities/meta.h b/src/utilities/meta.h new file mode 100644 index 0000000..83cc0e2 --- /dev/null +++ b/src/utilities/meta.h @@ -0,0 +1,95 @@ +/* This file is part of the OpenLB library + * + * Copyright (C) 2019 Adrian Kummerlaender + * E-mail contact: info@openlb.net + * The most recent release of OpenLB can be downloaded at + * <http://www.openlb.net/> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the Free + * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301, USA. +*/ + +#ifndef UTILITIES_META_H +#define UTILITIES_META_H + +#include <type_traits> + +namespace olb { + +namespace utilities { + +namespace meta { + +/// Provide implementation of std::enable_if_t +/** + * Weirdly version 18.0.3 of the Intel C++ compiler doesn't provide this + * useful template alias despite otherwise supporting C++14. + **/ +template<bool B, class T = void> +using enable_if_t = typename std::enable_if<B,T>::type; + +/// Check whether a given type list contains WANTED +template < + typename WANTED, + typename HEAD = void, // Default argument in case the list is empty + typename... TAIL +> +struct list_contains_item { + using type = typename std::conditional< + std::is_same<WANTED, HEAD>::value, + std::true_type, + typename list_contains_item<WANTED, TAIL...>::type + >::type; +}; + +template <typename WANTED, typename HEAD> +struct list_contains_item<WANTED, HEAD> { + using type = typename std::is_same<WANTED, HEAD>::type; +}; + + +/// Get first type based on BASE contained in a given type list +/** + * If no such list item exists, type is void. + **/ +template < + typename BASE, + typename HEAD = void, // Default argument in case the list is empty + typename... TAIL +> +struct list_item_with_base { + using type = typename std::conditional< + std::is_base_of<BASE, HEAD>::value, + HEAD, + typename list_item_with_base<BASE, TAIL...>::type + >::type; +}; + +template <typename BASE, typename HEAD> +struct list_item_with_base<BASE, HEAD> { + using type = typename std::conditional< + std::is_base_of<BASE, HEAD>::value, + HEAD, + void + >::type; +}; + +} + +} + +} + +#endif |