Mercurial > hg > CbC > CbC_gcc
view gcc/testsuite/g++.dg/cpp0x/sfinae54.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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// PR c++/63723 // { dg-do compile { target c++11 } } template<typename Tp> Tp declval(); template<typename Tp, Tp v> struct integral_constant { static constexpr Tp value = v; typedef Tp value_type; typedef integral_constant<Tp, v> type; constexpr operator value_type() const { return value; } }; typedef integral_constant<bool, true> true_type; typedef integral_constant<bool, false> false_type; template <typename From, typename To> class is_list_convertible_helper { template <typename To2> static void requires_conversion(To2 t); template <typename From2, typename To2, typename = decltype(requires_conversion<To2>({declval<From2>()}))> static true_type helper(int); template <typename From2, typename To2> static false_type helper(...); public: using type = decltype(helper<From, To>(0)); }; template <typename From, typename To> class is_list_convertible : public is_list_convertible_helper<From, To>::type { }; static_assert(!is_list_convertible<double, int>::value, "double -> int is narrowing!");