Mercurial > hg > CbC > CbC_gcc
view gcc/testsuite/g++.dg/concepts/variadic2.C @ 145:1830386684a0
gcc-9.2.0
author | anatofuz |
---|---|
date | Thu, 13 Feb 2020 11:34:05 +0900 |
parents | 84e7813d76e9 |
children |
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// { dg-do compile { target c++17_only } } // { dg-options "-fconcepts" } template <class T> concept bool Copyable = requires (T t) { T(t); }; template <class T> concept bool Constructable = requires { T(); }; template <class T> concept bool Both = Copyable<T> && Constructable<T>; template <Copyable... Ts> // requires (Copyable<Ts> && ...) constexpr int f(Ts...) { return 0; } // #1 template <Both... Ts> // requires (Both<Ts> && ...) constexpr int f(Ts...) { return 1; } // #2 int main() { static_assert(f(42) == 1); // { dg-error "ambiguous" } // The associated constraints of the two functions are incomparable. }