Mercurial > hg > CbC > CbC_gcc
view gcc/testsuite/g++.dg/cpp2a/concepts-requires10.C @ 145:1830386684a0
gcc-9.2.0
author | anatofuz |
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date | Thu, 13 Feb 2020 11:34:05 +0900 |
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// PR c++/66988 // { dg-do compile { target c++2a } } template<bool B> struct bool_constant { static constexpr bool value = B; constexpr operator bool() const { return value; } }; using true_type = bool_constant<true>; using false_type = bool_constant<false>; template <template <class> class T, class U> concept _Valid = requires { typename T<U>; }; template <class T> using nested_type = typename T::type; template <class T> struct has_nested_type : false_type { }; template <class T> requires _Valid<nested_type, T> struct has_nested_type<T> : true_type { }; struct Nested { using type = int; }; static_assert(!has_nested_type<int>()); static_assert(has_nested_type<Nested>());