view gcc/testsuite/g++.dg/cpp2a/concepts-partial-spec6.C @ 145:1830386684a0

gcc-9.2.0
author anatofuz
date Thu, 13 Feb 2020 11:34:05 +0900
parents
children
line wrap: on
line source

// PR c++/67152
// { dg-do compile { target c++2a } }

template <class T>
concept HasType = requires { typename T::type; };

template<class T>
struct trait {
  using type = void;
};

struct has_type { using type = void; };

// Instantiation here
trait<has_type>::type foo() {}

// constrained version here. Type "has_type" would fail this
// constraint so this partial specialization would not have been
// selected.
template<class T>
  requires (!HasType<T>)
struct trait<T> {
  using type = void;
};