1 // RUN: %clang_cc1 -std=c++2a -verify %s 2 3 // Make sure constraint expressions are unevaluated before being substituted 4 // into during satisfaction checking. 5 6 template<typename T> constexpr bool f = T::value; 7 // expected-error@-1 4{{type}} 8 9 namespace unevaluated { 10 template<typename T> concept Foo = false && f<int>; 11 bool k = Foo<int>; 12 template<typename T> requires false && f<int> struct S {}; 13 // expected-note@-1{{because}} 14 using s = S<int>; // expected-error {{constraints not satisfied}} foo()15 template<typename T> void foo() requires false && f<int> { }; 16 // expected-note@-1{{because}} expected-note@-1{{candidate template ignored}} 17 int a = (foo<int>(), 0); // expected-error{{no matching function}} bar()18 template<typename T> void bar() requires requires { requires false && f<int>; } { }; 19 // expected-note@-1{{because}} expected-note@-1{{candidate template ignored}} 20 int b = (bar<int>(), 0); // expected-error{{no matching function}} foounevaluated::M21 template<typename T> struct M { static void foo() requires false && f<int> { }; }; 22 // expected-note@-1{{because}} 23 int c = (M<int>::foo(), 0); 24 // expected-error@-1{{invalid reference to function 'foo': constraints not satisfied}} 25 } 26 27 namespace constant_evaluated { 28 template<typename T> requires f<int[0]> struct S {}; 29 // expected-note@-1{{in instantiation of}} expected-note@-1{{while substituting}} 30 using s = S<int>; 31 // expected-note@-1 {{while checking}} foo()32 template<typename T> void foo() requires f<int[1]> { }; 33 // expected-note@-1{{in instantiation}} expected-note@-1{{while substituting}} \ 34 expected-note@-1{{candidate template ignored}} 35 int a = (foo<int>(), 0); 36 // expected-note@-1 {{while checking}} expected-error@-1{{no matching function}} \ 37 expected-note@-1 {{in instantiation}} bar()38 template<typename T> void bar() requires requires { requires f<int[2]>; } { }; 39 // expected-note@-1{{in instantiation}} \ 40 expected-note@-1{{while substituting}} \ 41 expected-note@-1 {{while checking the satisfaction of nested requirement}} 42 int b = (bar<int>(), 0); fooconstant_evaluated::M43 template<typename T> struct M { static void foo() requires f<int[3]> { }; }; 44 // expected-note@-1{{in instantiation}} expected-note@-1{{while substituting}} 45 int c = (M<int>::foo(), 0); 46 // expected-note@-1 {{while checking}} 47 } 48