93 lines · cpp
1// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s2 3template <typename T, typename U = void*>4struct A {5 enum {6 id = _Generic(T{}, // expected-error {{controlling expression type 'char' not compatible with any generic association type}}7 int: 1, // expected-note {{compatible type 'int' specified here}}8 float: 2,9 U: 3) // expected-error {{type 'int' in generic association compatible with previously specified type 'int'}}10 };11};12 13static_assert(A<int>::id == 1, "fail");14static_assert(A<float>::id == 2, "fail");15static_assert(A<double, double>::id == 3, "fail");16 17A<char> a1; // expected-note {{in instantiation of template class 'A<char>' requested here}}18A<short, int> a2; // expected-note {{in instantiation of template class 'A<short, int>' requested here}}19 20template <typename T, typename U>21struct B {22 enum {23 id = _Generic(T{},24 int: 1, // expected-note {{compatible type 'int' specified here}}25 int: 2, // expected-error {{type 'int' in generic association compatible with previously specified type 'int'}}26 U: 3)27 };28};29 30template <unsigned Arg, unsigned... Args> struct Or {31 enum { result = Arg | Or<Args...>::result };32};33 34template <unsigned Arg> struct Or<Arg> {35 enum { result = Arg };36};37 38template <class... Args> struct TypeMask {39 enum {40 result = Or<_Generic(Args{}, int: 1, long: 2, short: 4, float: 8)...>::result41 };42};43 44static_assert(TypeMask<int, long, short>::result == 7, "fail");45static_assert(TypeMask<float, short>::result == 12, "fail");46static_assert(TypeMask<int, float, float>::result == 9, "fail");47 48 49struct Test {50 int i;51};52 53void unreachable_associations(const int i, const Test t) {54 // FIXME: it's not clear to me whether we intended to deviate from the C55 // semantics in terms of how qualifiers are handled, so this documents the56 // existing behavior but perhaps not the desired behavior.57 static_assert(58 _Generic(i,59 const int : 1, // expected-warning {{due to lvalue conversion of the controlling expression, association of type 'const int' will never be selected because it is qualified}}60 volatile int : 2, // expected-warning {{due to lvalue conversion of the controlling expression, association of type 'volatile int' will never be selected because it is qualified}}61 int[12] : 3, // expected-warning {{due to lvalue conversion of the controlling expression, association of type 'int[12]' will never be selected because it is of array type}}62 int : 4,63 default : 564 ) == 4, "we had better pick int, not const int!");65 static_assert(66 _Generic(t,67 Test : 1,68 const Test : 2, // Ok in C++, warned in C69 default : 370 ) == 2, "we had better pick const Test, not Test!"); // C++-specific result71}72 73namespace GH55562 {74struct S { // expected-note {{declared here}}75 int i;76};77 78void func(struct S s) {79 // We would previously reject this because the parser thought 'struct S :'80 // was the start of a definition (with a base class specifier); it's not, it81 // is an elaborated type specifier followed by the association's value and82 // it should work the same as in C.83 (void)_Generic(s, struct S : 1);84 (void)_Generic(s, struct T : 1); // expected-error {{controlling expression type 'struct S' not compatible with any generic association type}}85 86 // The rest of these cases test that we still produce a reasonable diagnostic87 // when referencing an unknown type or trying to define a type in other ways.88 (void)_Generic(s, struct U { int a; } : 1); // expected-error {{'U' cannot be defined in a type specifier}}89 (void)_Generic(s, struct V : S); // expected-error {{'S' does not refer to a value}}90 (void)_Generic(s, struct W : S { int b; } : 1); // expected-error {{expected '(' for function-style cast or type construction}}91}92} // namespace GH5556293