35 lines · cpp
1// RUN: %clang_cc1 -std=c++2a -verify %s2 3// When forming and checking satisfaction of atomic constraints, we will4// substitute still-dependent template arguments into an expression, and later5// substitute into the result. This creates some unique situations; check that6// they work.7 8namespace SubstIntoResolvedTypeTemplateArg {9 template<int, class> struct X {};10 11 template<class T> concept A = true;12 template<class T> concept B = sizeof(T) != 0;13 template<class T> concept C = B<X<1, T>>;14 15 int f(A auto); // expected-note {{candidate}}16 int f(C auto); // expected-note {{candidate}}17 int k1 = f(0); // expected-error {{ambiguous}}18 19 template<class T> concept D = A<T> && B<X<1, T>>;20 int f(D auto);21 int k2 = f(0); // ok22 23 // The atomic constraint formed from B<X<(int)'\1', T>> is identical to the24 // one formed from C, even though the template arguments are written as25 // different expressions; the "equivalent" rules are used rather than the26 // "identical" rules when matching template arguments in concept-ids.27 template<class T> concept E = A<T> && B<X<(int)'\1', T>>;28 int g(C auto);29 int g(E auto); // expected-note {{candidate}}30 int k3 = g(0);31 32 int g(D auto); // expected-note {{candidate}}33 int k4 = g(0); // expected-error {{ambiguous}}34}35