Mercurial > hg > CbC > CbC_gcc
view gcc/testsuite/g++.dg/template/sfinae12.C @ 131:84e7813d76e9
gcc-8.2
author | mir3636 |
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date | Thu, 25 Oct 2018 07:37:49 +0900 |
parents | 04ced10e8804 |
children |
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// DR 339 // // Test of the use of the ternary operator with SFINAE // Boilerplate helpers typedef char yes_type; struct no_type { char data[2]; }; template<typename T> T create_a(); template<typename T> struct type { }; template<bool, typename T = void> struct enable_if { typedef T type; }; template<typename T> struct enable_if<false, T> { }; #define JOIN( X, Y ) DO_JOIN( X, Y ) #define DO_JOIN( X, Y ) DO_JOIN2(X,Y) #define DO_JOIN2( X, Y ) X##Y template<typename T, typename U, typename V> typename enable_if< (sizeof((create_a<T>()? create_a<U>() : create_a<V>()), 0) > 0), yes_type>::type check_ternary(int); template<typename T, typename U, typename V> no_type check_ternary(...); template<typename T, typename U, typename V> struct has_ternary { static const bool value = (sizeof(check_ternary<T, U, V>(0)) == sizeof(yes_type)); }; #ifdef __GXX_EXPERIMENTAL_CXX0X__ # define STATIC_ASSERT(Expr) static_assert(Expr, #Expr) #else # define STATIC_ASSERT(Expr) int JOIN(a,__LINE__)[Expr? 1 : -1] #endif struct X { }; struct Y { operator bool(); }; STATIC_ASSERT((has_ternary<int, float, double>::value)); STATIC_ASSERT((has_ternary<bool, double, double>::value)); STATIC_ASSERT((!has_ternary<int, float*, double>::value)); STATIC_ASSERT((!has_ternary<X, double, double>::value)); STATIC_ASSERT((has_ternary<Y, double, double>::value));