1 //================================================================================================= 2 /*! 3 // \file blaze/math/typetraits/IsEvalExpr.h 4 // \brief Header file for the IsEvalExpr type trait class 5 // 6 // Copyright (C) 2012-2020 Klaus Iglberger - All Rights Reserved 7 // 8 // This file is part of the Blaze library. You can redistribute it and/or modify it under 9 // the terms of the New (Revised) BSD License. Redistribution and use in source and binary 10 // forms, with or without modification, are permitted provided that the following conditions 11 // are met: 12 // 13 // 1. Redistributions of source code must retain the above copyright notice, this list of 14 // conditions and the following disclaimer. 15 // 2. Redistributions in binary form must reproduce the above copyright notice, this list 16 // of conditions and the following disclaimer in the documentation and/or other materials 17 // provided with the distribution. 18 // 3. Neither the names of the Blaze development group nor the names of its contributors 19 // may be used to endorse or promote products derived from this software without specific 20 // prior written permission. 21 // 22 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY 23 // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 25 // SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 27 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 28 // BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 30 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 31 // DAMAGE. 32 */ 33 //================================================================================================= 34 35 #ifndef _BLAZE_MATH_TYPETRAITS_ISEVALEXPR_H_ 36 #define _BLAZE_MATH_TYPETRAITS_ISEVALEXPR_H_ 37 38 39 //************************************************************************************************* 40 // Includes 41 //************************************************************************************************* 42 43 #include <utility> 44 #include <blaze/math/expressions/EvalExpr.h> 45 #include <blaze/util/IntegralConstant.h> 46 47 48 namespace blaze { 49 50 //================================================================================================= 51 // 52 // CLASS DEFINITION 53 // 54 //================================================================================================= 55 56 //************************************************************************************************* 57 /*! \cond BLAZE_INTERNAL */ 58 /*!\brief Auxiliary helper functions for the IsEvalExpr type trait. 59 // \ingroup math_type_traits 60 */ 61 template< typename U > 62 TrueType isEvalExpr_backend( const volatile EvalExpr<U>* ); 63 64 FalseType isEvalExpr_backend( ... ); 65 /*! \endcond */ 66 //************************************************************************************************* 67 68 69 //************************************************************************************************* 70 /*!\brief Compile time check whether the given type is an evaluation expression template. 71 // \ingroup math_type_traits 72 // 73 // This type trait class tests whether or not the given type \a Type is an evaluation expression 74 // template. In order to qualify as a valid evaluation expression template, the given type has 75 // to derive publicly from the EvalExpr base class. In case the given type is a valid evaluation 76 // expression template, the \a value member constant is set to \a true, the nested type definition 77 // \a Type is \a TrueType, and the class derives from \a TrueType. Otherwise \a value is set to 78 // \a false, \a Type is \a FalseType, and the class derives from \a FalseType. 79 */ 80 template< typename T > 81 struct IsEvalExpr 82 : public decltype( isEvalExpr_backend( std::declval<T*>() ) ) 83 {}; 84 //************************************************************************************************* 85 86 87 //************************************************************************************************* 88 /*! \cond BLAZE_INTERNAL */ 89 /*!\brief Specialization of the IsEvalExpr type trait for references. 90 // \ingroup math_type_traits 91 */ 92 template< typename T > 93 struct IsEvalExpr<T&> 94 : public FalseType 95 {}; 96 /*! \endcond */ 97 //************************************************************************************************* 98 99 100 //************************************************************************************************* 101 /*!\brief Auxiliary variable template for the IsEvalExpr type trait. 102 // \ingroup math_type_traits 103 // 104 // The IsEvalExpr_v variable template provides a convenient shortcut to access the nested 105 // \a value of the IsEvalExpr class template. For instance, given the type \a T the following 106 // two statements are identical: 107 108 \code 109 constexpr bool value1 = blaze::IsEvalExpr<T>::value; 110 constexpr bool value2 = blaze::IsEvalExpr_v<T>; 111 \endcode 112 */ 113 template< typename T > 114 constexpr bool IsEvalExpr_v = IsEvalExpr<T>::value; 115 //************************************************************************************************* 116 117 } // namespace blaze 118 119 #endif 120