// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
// New exciting ambiguities in C++11
// final 'context sensitive' mess.
namespace final {
struct S { int n; };
struct T { int n; };
namespace N {
int n;
// These declare variables named final..
extern struct S final;
extern struct S final [[]];
extern struct S final, foo;
struct S final = S();
// This defines a class, not a variable, even though it would successfully
// parse as a variable but not as a class. DR1318's wording suggests that
// this disambiguation is only performed on an ambiguity, but that was not
// the intent.
struct S final { // expected-note {{here}}
int(n) // expected-error {{expected ';'}}
};
// This too.
struct T final : S {}; // expected-error {{base 'S' is marked 'final'}}
struct T bar : S {}; // expected-error {{expected ';' after top level declarator}} expected-error {{expected unqualified-id}}
}
// _Alignas isn't allowed in the places where alignas is. We used to
// assert on this.
struct U final _Alignas(4) {}; // expected-error 3{{}} expected-note {{}}
}
// enum versus bitfield. These are always required to be treated as an
// enum-base, but we disambiguate anyway for better error recovery.
namespace bitfield {
enum E {};
struct T {
constexpr T() {}
constexpr T(int) {}
constexpr T(T, T, T, T) {}
constexpr T operator=(T) const { return *this; }
constexpr operator int() const { return 4; }
};
constexpr T a, b, c, d;
struct S1 {
enum E : T ( a = 1, b = 2, c = 3, 4 ); // expected-error {{ISO C++ only allows ':' in member enumeration declaration to introduce a fixed underlying type, not an anonymous bit-field}}
};
// Enum definition, not a bit-field.
struct S2 {
enum E : T { a = 1, b = 2, c = 3, 4 }; // expected-error {{non-integral type}} expected-error {{expected identifier}}
};
struct S3 {
enum E : int { a = 1, b = 2, c = 3, d }; // ok, defines an enum
};
// Ambiguous.
struct S4 {
enum E : int { a = 1 }; // ok, defines an enum
};
// This could be a bit-field, but would be ill-formed due to the anonymous
// member being initialized.
struct S5 {
enum E : int { a = 1 } { b = 2 }; // expected-error {{expected ';' after enum}} expected-error {{expected member name}}
};
// This could be a bit-field.
struct S6 {
enum E : int { 1 }; // expected-error {{expected identifier}}
};
struct U {
constexpr operator T() const { return T(); } // expected-note 2{{candidate}}
};
// This could be a bit-field.
struct S7 {
enum E : int { a = U() }; // expected-error {{no viable conversion}}
};
// This could be a bit-field, and does not conform to the grammar of an
// enum definition, because 'id(U())' is not a constant-expression.
constexpr const U &id(const U &u) { return u; }
struct S8 {
enum E : int { a = id(U()) }; // expected-error {{no viable conversion}}
};
// PR26249: Disambiguate 'enum :' as an enum-base always, even if that would
// be ill-formed. It cannot be an elaborated-type-specifier.
struct S {
enum : undeclared_type { v = 0 }; // expected-error {{unknown type name 'undeclared_type'}}
enum E : undeclared_type { w = 0 }; // expected-error {{unknown type name 'undeclared_type'}}
enum X : undeclared_type { x = 0 }; // expected-error {{unknown type name 'undeclared_type'}}
};
}
namespace trailing_return {
typedef int n;
int a;
struct S {
S(int);
S *operator()(...) const;
int n;
};
namespace N {
void f() {
// This parses as a function declaration, but DR1223 makes the presence of
// 'auto' be used for disambiguation.
S(a)()->n; // ok, expression; expected-warning{{expression result unused}}
S(a)(int())->n; // ok, expression; expected-warning{{expression result unused}}
auto(a)()->n; // ok, function declaration
auto(b)(int())->n; // ok, function declaration
using T = decltype(a);
using T = auto() -> n;
}
}
}
namespace ellipsis {
template<typename...T>
struct S {
void e(S::S()); // expected-error {{is a constructor name}}
void f(S(...args[sizeof(T)])); // expected-note {{here}} expected-note {{here}}
void f(S(...args)[sizeof(T)]); // expected-error {{redeclared}}
void f(S ...args[sizeof(T)]); // expected-error {{redeclared}}
void g(S(...[sizeof(T)])); // expected-warning {{ISO C++11 requires a parenthesized pack declaration to have a name}}
void g(S(...)[sizeof(T)]); // expected-error {{function cannot return array type}}
void h(T(...)); // function type, expected-error {{unexpanded parameter pack}}
void h(T...); // pack expansion, ok
void i(int(T...)); // expected-note {{here}}
void i(int(T...a)); // expected-error {{redeclared}}
void i(int(T, ...)); // function type, expected-error {{unexpanded parameter pack}}
void i(int(T, ...a)); // expected-error {{expected ')'}} expected-note {{to match}} expected-error {{unexpanded parameter pack}}
void j(int(int...)); // function type, ok
void j(int(int...a)); // expected-error {{does not contain any unexpanded parameter packs}}
void j(T(int...)); // expected-error {{unexpanded parameter pack}}
void j(T(T...)); // expected-error {{unexpanded parameter pack}}
void k(int(...)(T)); // expected-error {{cannot return function type}}
void k(int ...(T));
void l(int(&...)(T)); // expected-warning {{ISO C++11 requires a parenthesized pack declaration to have a name}}
void l(int(*...)(T)); // expected-warning {{ISO C++11 requires a parenthesized pack declaration to have a name}}
void l(int(S<int>::*...)(T)); // expected-warning {{ISO C++11 requires a parenthesized pack declaration to have a name}}
};
struct CtorSink {
template <typename ...T> constexpr CtorSink(T &&...t) { }
constexpr operator int() const { return 42; }
};
template <unsigned ...N> struct UnsignedTmplArgSink;
template <typename ...T>
void foo(int x, T ...t) {
// Have a variety of cases where the syntax is technically unambiguous, but hinges on careful treatment of ellipses.
CtorSink(t ...), x; // ok, expression; expected-warning 2{{expression result unused}}
int x0(CtorSink(t ...)); // ok, declares object x0
int *p0 = &x0;
(void)p0;
CtorSink x1(int(t) ..., int(x)); // ok, declares object x1
CtorSink *p1 = &x1;
(void)p1;
UnsignedTmplArgSink<T(CtorSink(t ...)) ...> *t0; // ok
UnsignedTmplArgSink<((T *)0, 42u) ...> **t0p = &t0; // expected-warning 2{{left operand of comma operator has no effect}}
}
template void foo(int, int, int); // expected-note {{in instantiation of function template specialization 'ellipsis::foo<int, int>' requested here}}
}
namespace braced_init_list {
struct X {
void foo() {}
};
void (*pf1)() {};
void (X::*pmf1)() {&X::foo};
void (X::*pmf2)() = {&X::foo};
void test() {
void (*pf2)() {};
void (X::*pmf3)() {&X::foo};
void (X::*pmf4)() = {&X::foo};
}
}
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