1*12938cf8SRichard Smith // RUN: %clang_cc1 -std=c++17 -verify %s 2*12938cf8SRichard Smith not_constexpr()3*12938cf8SRichard Smithtemplate<typename T> int not_constexpr() { return T::error; } is_constexpr()4*12938cf8SRichard Smithtemplate<typename T> constexpr int is_constexpr() { return T::error; } // expected-error {{'::'}} 5*12938cf8SRichard Smith 6*12938cf8SRichard Smith template<typename T> int not_constexpr_var = T::error; 7*12938cf8SRichard Smith template<typename T> constexpr int is_constexpr_var = T::error; // expected-error {{'::'}} 8*12938cf8SRichard Smith template<typename T> const int is_const_var = T::error; // expected-error {{'::'}} 9*12938cf8SRichard Smith template<typename T> const volatile int is_const_volatile_var = T::error; 10*12938cf8SRichard Smith template<typename T> T is_dependent_var = T::error; // expected-error {{'::'}} 11*12938cf8SRichard Smith template<typename T> int &is_reference_var = T::error; // expected-error {{'::'}} 12*12938cf8SRichard Smith template<typename T> float is_float_var = T::error; 13*12938cf8SRichard Smith test()14*12938cf8SRichard Smithvoid test() { 15*12938cf8SRichard Smith // Do not instantiate functions referenced in unevaluated operands... 16*12938cf8SRichard Smith (void)sizeof(not_constexpr<long>()); 17*12938cf8SRichard Smith (void)sizeof(is_constexpr<long>()); 18*12938cf8SRichard Smith (void)sizeof(not_constexpr_var<long>); 19*12938cf8SRichard Smith (void)sizeof(is_constexpr_var<long>); 20*12938cf8SRichard Smith (void)sizeof(is_const_var<long>); 21*12938cf8SRichard Smith (void)sizeof(is_const_volatile_var<long>); 22*12938cf8SRichard Smith (void)sizeof(is_dependent_var<long>); 23*12938cf8SRichard Smith (void)sizeof(is_dependent_var<const long>); 24*12938cf8SRichard Smith (void)sizeof(is_reference_var<long>); 25*12938cf8SRichard Smith (void)sizeof(is_float_var<long>); 26*12938cf8SRichard Smith 27*12938cf8SRichard Smith // ... but do if they are potentially constant evaluated, and refer to 28*12938cf8SRichard Smith // constexpr functions or to variables usable in constant expressions. 29*12938cf8SRichard Smith (void)sizeof(int{not_constexpr<int>()}); 30*12938cf8SRichard Smith (void)sizeof(int{is_constexpr<int>()}); // expected-note {{instantiation of}} 31*12938cf8SRichard Smith (void)sizeof(int{not_constexpr_var<int>}); 32*12938cf8SRichard Smith (void)sizeof(int{is_constexpr_var<int>}); // expected-note {{instantiation of}} 33*12938cf8SRichard Smith (void)sizeof(int{is_const_var<int>}); // expected-note {{instantiation of}} 34*12938cf8SRichard Smith (void)sizeof(int{is_const_volatile_var<int>}); 35*12938cf8SRichard Smith (void)sizeof(int{is_dependent_var<int>}); 36*12938cf8SRichard Smith (void)sizeof(int{is_dependent_var<const int>}); // expected-note {{instantiation of}} 37*12938cf8SRichard Smith (void)sizeof(int{is_reference_var<int>}); // expected-note {{instantiation of}} 38*12938cf8SRichard Smith (void)sizeof(int{is_float_var<int>}); // expected-error {{cannot be narrowed}} expected-note {{cast}} 39*12938cf8SRichard Smith } 40