Re: Pass by const-reference, temporaries and copyability

function taking a const-reference requires being able to copy that
temporary.

GCC 4.2 does confirm it with the following code:

struct Foo
{
     Foo() {}
private:
     Foo(const Foo&);

};

void test(const Foo&) {}

int main()
{
     test(Foo());

}

I get the error that Foo(const Foo&) is not accessible.

It seems however that GCC 4.3 changed that behaviour: the code
compiles successfully, even in standard compliant pedantic mode with
all warnings.

While I do like the new behaviour much better (there is really no need
to be able to copy there, and it's just an annoyance that makes
handling of non-copyable types difficult) I think it is incorrect.

Is my memory of the standard incorrect, or was it changed? What does C+
+0x have to say about this? I suppose rvalue references do not require
copyability, so passing by const-rvalue-reference could be a better
idiom.