Re: reference to non-const temporary
Ethan Eade wrote:
Consider the following: The failures apply to g++ 3.3.3 and 3.4, but
not 4.01, which happily compiles when line '***' is not present. Should
it always work according to the standard?
//-------------------------------------------------
struct Foo {
void foo() {}
operator Foo& () { return *this; } // ***
};
Foo make() { return Foo(); }
void use(Foo& foo) {}
int main()
{
// This line always works
make().foo();
// This line fails when *** is commented out
// using g++ 3.3.3 and 3.4
use(make());
}
The compiler should ignore the operator Foo&() conversion method when
converting a Foo to a Foo&, so whether the method is commented in or
out should make no difference to the compiler. Since a temporary cannot
be passed as a non-const reference parameter, the use() function call
should not compile successfully in both cases. (?12.3.2/1 prohibits a
conversion method from being called to convert an object to a reference
to the object's type.)
Greg
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