utl/include/utl/concepts/defines.h

/*!
 * \file   /utl/concepts/defines.h
 * \brief  Concepts defines
 *
 * 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 <http://www.gnu.org/licenses/>.
 *
 */
#ifndef __utl_concepts_defines_h__
#define __utl_concepts_defines_h__

//!\defgroup concepts
//!@{

/*!
 * \brief
 *    utl typename constraints wrapper
 *
 * \example
 * \code
 *    template <utlConstrainType(SomeConcept) T> struct lala { };
 *    // will expand to something like:
 *    // template <SomeConcept T> struct lala { };
 *    // or
 *    // template <typename T> struct lala { };
 * \endcode
 */
#if CXX_CONCEPTS
   #define utlConstrainType(_Concept_)   _Concept_
#else
   #define utlConstrainType(_Concept_)   typename
#endif

/*! \brief
 *    utl concept keyword syntax wrapper
 */
#if CXX_CONCEPTS
 #if __cpp_concepts <= 201507L
   #define _utlConcept   concept bool
 #else
   #define _utlConcept   concept
 #endif
#else
  #define _utlConcept    constexpr bool
#endif

#ifndef CXX_LIB_INVOKE
 #ifdef __cpp_lib_invoke
  #define CXX_LIB_INVOKE __cpp_lib_invoke
 #else
   #define CXX_LIB_INVOKE 0
 #endif
#endif

//! @}

#endif /* __utl_concepts_defines_h__ */