1 // { dg-options "-std=c++17 -fconcepts" }
4 concept bool C1 = __is_same_as(T, int);
7 concept bool C2 = N == 0;
9 template<template<typename> class X>
10 concept bool C3 = true;
12 template<typename> struct Foo;
14 template<C1... Ts = int> struct S1; // { dg-error "default argument" }
15 template<C1... = int> struct S2; // { dg-error "default argument" }
16 template<C2... Ns = 0> struct S3; // { dg-error "default argument" }
17 template<C2... = 0> struct S4; // { dg-error "default argument" }
18 template<C3... Ts = Foo> struct S5; // { dg-error "default argument" }
19 template<C3... = Foo> struct S6; // { dg-error "default argument" }