llvm-project/clang/test/SemaCXX/conversion-function.cpp

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// RUN: clang-cc -fsyntax-only -verify %s
class X {
public:
operator bool();
operator int() const;
bool f() {
return operator bool();
}
float g() {
return operator float(); // expected-error{{no matching function for call to 'operator float'}}
}
};
operator int(); // expected-error{{conversion function must be a non-static member function}}
operator int; // expected-error{{'operator int' cannot be the name of a variable or data member}}
typedef int func_type(int);
typedef int array_type[10];
class Y {
public:
void operator bool(int, ...) const; // expected-error{{conversion function cannot have a return type}} \
// expected-error{{conversion function cannot have any parameters}}
operator float(...) const; // expected-error{{conversion function cannot be variadic}}
operator func_type(); // expected-error{{conversion function cannot convert to a function type}}
operator array_type(); // expected-error{{conversion function cannot convert to an array type}}
};
typedef int INT;
typedef INT* INT_PTR;
class Z {
operator int(); // expected-note {{previous declaration is here}}
operator int**(); // expected-note {{previous declaration is here}}
operator INT(); // expected-error{{conversion function cannot be redeclared}}
operator INT_PTR*(); // expected-error{{conversion function cannot be redeclared}}
};
class A { };
class B : public A {
public:
operator A&() const; // expected-warning{{conversion function converting 'class B' to its base class 'class A' will never be used}}
operator const void() const; // expected-warning{{conversion function converting 'class B' to 'void const' will never be used}}
operator const B(); // expected-warning{{conversion function converting 'class B' to itself will never be used}}
};
// This used to crash Clang.
struct Flip;
struct Flop {
Flop();
Flop(const Flip&);
};
struct Flip {
operator Flop() const;
};
Flop flop = Flip(); // expected-error {{cannot initialize 'flop' with an rvalue of type 'struct Flip'}}
// This tests that we don't add the second conversion declaration to the list of user conversions
struct C {
operator const char *() const;
};
C::operator const char*() const { return 0; }
void f(const C& c) {
const char* v = c;
}
// Test. Conversion in base class is visible in derived class.
class XB {
public:
operator int(); // expected-note {{candidate function}}
};
class Yb : public XB {
public:
operator char(); // expected-note {{candidate function}}
};
void f(Yb& a) {
if (a) { } // expected-error {{conversion from 'class Yb' to 'bool' is ambiguous}}
int i = a; // OK. calls XB::operator int();
char ch = a; // OK. calls Yb::operator char();
}