Mercurial > hg > CbC > CbC_gcc
view gcc/testsuite/g++.dg/template/sfinae14.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 new and new[] operators 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 enable_if<(sizeof(new T, 0) > 0), yes_type>::type check_new(int); template<typename T> no_type check_new(...); template<typename T> struct has_new { static const bool value = (sizeof(check_new<T>(0)) == sizeof(yes_type)); }; template<typename T, typename U> typename enable_if<(sizeof((new T(create_a<U>())), 0) > 0), yes_type>::type check_new_one_arg(int); template<typename T, typename U> no_type check_new_one_arg(...); template<typename T, typename U> struct has_new_one_arg { static const bool value = (sizeof(check_new_one_arg<T, U>(0)) == sizeof(yes_type)); }; template<typename T, typename U, U N> typename enable_if<(sizeof(new T[N], 0) > 0), yes_type>::type check_array_new(int); template<typename T, typename U, U N> no_type check_array_new(...); template<typename T, typename U, U N> struct has_array_new { static const bool value = (sizeof(check_array_new<T, U, N>(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 { X(int); }; struct Y { int foo; }; STATIC_ASSERT((has_new<Y>::value)); STATIC_ASSERT(!(has_new<X>::value)); STATIC_ASSERT((has_new_one_arg<Y, Y>::value)); STATIC_ASSERT((has_new_one_arg<X, float>::value)); STATIC_ASSERT(!(has_new_one_arg<X, int X::*>::value)); STATIC_ASSERT((has_array_new<Y, int, 5>::value)); STATIC_ASSERT(!(has_array_new<X, int Y::*, &Y::foo>::value)); STATIC_ASSERT((has_array_new<X, int, 5>::value));