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

328 lines
7.0 KiB
C++

// RUN: %clang_cc1 -fsyntax-only -verify %s
class X {
public:
operator bool();
operator int() const;
bool f() {
return operator bool();
}
float g() {
return operator float(); // expected-error{{use of undeclared '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 'B' to its base class 'A' will never be used}}
operator const void() const; // expected-warning{{conversion function converting 'B' to 'void const' will never be used}}
operator const B(); // expected-warning{{conversion function converting 'B' to itself will never be used}}
};
// This used to crash Clang.
struct Flip;
struct Flop {
Flop();
Flop(const Flip&); // expected-note{{candidate constructor}}
};
struct Flip {
operator Flop() const; // expected-note{{candidate function}}
};
Flop flop = Flip(); // expected-error {{conversion from 'Flip' to 'Flop' is ambiguous}}
// 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 'Yb' to 'bool' is ambiguous}}
int i = a; // OK. calls XB::operator int();
char ch = a; // OK. calls Yb::operator char();
}
// Test conversion + copy construction.
class AutoPtrRef { };
class AutoPtr {
AutoPtr(AutoPtr &); // expected-note{{declared private here}}
public:
AutoPtr();
AutoPtr(AutoPtrRef);
operator AutoPtrRef();
};
AutoPtr make_auto_ptr();
AutoPtr test_auto_ptr(bool Cond) {
AutoPtr p1( make_auto_ptr() );
AutoPtr p;
if (Cond)
return p; // expected-error{{calling a private constructor}}
return AutoPtr();
}
struct A1 {
A1(const char *);
~A1();
private:
A1(const A1&); // expected-note 2 {{declared private here}}
};
A1 f() {
// FIXME: redundant diagnostics!
return "Hello"; // expected-error {{calling a private constructor}} expected-warning {{an accessible copy constructor}}
}
namespace source_locations {
template<typename T>
struct sneaky_int {
typedef int type;
};
template<typename T, typename U>
struct A { };
template<typename T>
struct A<T, T> : A<T, int> { };
struct E {
template<typename T>
operator A<T, typename sneaky_int<T>::type>&() const; // expected-note{{candidate function}}
};
void f() {
A<float, float> &af = E(); // expected-error{{no viable conversion}}
A<float, int> &af2 = E();
const A<float, int> &caf2 = E();
}
// Check
template<typename T>
struct E2 {
operator T
* // expected-error{{pointer to a reference}}
() const;
};
E2<int&> e2i; // expected-note{{in instantiation}}
}
namespace crazy_declarators {
struct A {
(&operator bool())(); // expected-error {{must use a typedef to declare a conversion to 'bool (&)()'}}
// FIXME: This diagnostic is misleading (the correct spelling
// would be 'operator int*'), but it's a corner case of a
// rarely-used syntax extension.
*operator int(); // expected-error {{must use a typedef to declare a conversion to 'int *'}}
};
}
namespace smart_ptr {
class Y {
class YRef { };
Y(Y&);
public:
Y();
Y(YRef);
operator YRef(); // expected-note{{candidate function}}
};
struct X { // expected-note{{candidate constructor (the implicit copy constructor) not}}
explicit X(Y);
};
Y make_Y();
X f() {
X x = make_Y(); // expected-error{{no viable conversion from 'smart_ptr::Y' to 'smart_ptr::X'}}
X x2(make_Y());
return X(Y());
}
}
struct Any {
Any(...);
};
struct Other {
Other(const Other &);
Other();
};
void test_any() {
Any any = Other(); // expected-error{{cannot pass object of non-POD type 'Other' through variadic constructor; call will abort at runtime}}
}
namespace PR7055 {
// Make sure that we don't allow too many conversions in an
// auto_ptr-like template. In particular, we can't create multiple
// temporary objects when binding to a reference.
struct auto_ptr {
struct auto_ptr_ref { };
auto_ptr(auto_ptr&);
auto_ptr(auto_ptr_ref);
explicit auto_ptr(int *);
operator auto_ptr_ref();
};
struct X {
X(auto_ptr);
};
X f() {
X x(auto_ptr(new int));
return X(auto_ptr(new int));
}
auto_ptr foo();
X e(foo());
struct Y {
Y(X);
};
Y f2(foo());
}
namespace PR7934 {
typedef unsigned char uint8;
struct MutablePtr {
MutablePtr() : ptr(0) {}
void *ptr;
operator void*() { return ptr; }
private:
operator uint8*() { return reinterpret_cast<uint8*>(ptr); }
operator const char*() const { return reinterpret_cast<const char*>(ptr); }
};
void fake_memcpy(const void *);
void use() {
MutablePtr ptr;
fake_memcpy(ptr);
}
}
namespace rdar8018274 {
struct X { };
struct Y {
operator const struct X *() const;
};
struct Z : Y {
operator struct X * ();
};
void test() {
Z x;
(void) (x != __null);
}
struct Base {
operator int();
};
struct Derived1 : Base { };
struct Derived2 : Base { };
struct SuperDerived : Derived1, Derived2 {
using Derived1::operator int;
};
struct UeberDerived : SuperDerived {
operator long();
};
void test2(UeberDerived ud) {
int i = ud; // expected-error{{ambiguous conversion from derived class 'rdar8018274::SuperDerived' to base class 'rdar8018274::Base'}}
}
struct Base2 {
operator int();
};
struct Base3 {
operator int();
};
struct Derived23 : Base2, Base3 {
using Base2::operator int;
};
struct ExtraDerived23 : Derived23 { };
void test3(ExtraDerived23 ed) {
int i = ed;
}
}