| // { dg-do compile { target c++17_only } } |
| // { dg-options "-fconcepts" } |
| |
| template<typename T> |
| concept bool C1 = __is_same_as(T, int); |
| |
| template<int N> |
| concept bool C2 = N == 0; |
| |
| template<template<typename> class X> |
| concept bool C3 = true; |
| |
| template<typename> struct Foo; |
| |
| template<C1...> struct S1; |
| template<C1... Ts> struct S1 { }; |
| |
| template<C2...> struct S2; |
| template<C2... Ns> struct S2 { }; |
| |
| template<C3...> struct S3; |
| template<C3... Xs> struct S3 { }; |
| |
| S1<int, int, int> s1; // OK |
| S1<> s11; |
| S2<0, 0, 0> s2; |
| S2<> s22; |
| S3<Foo, Foo> s3; |
| S3<> s33; |
