Why assign const reference to non-const variable can't be displayed.

[q1670741824]

in main function, r can be displayed by cout, and when as a parameter assigned to const double &x, it just can't be displayed. only when type matched works.

void ref(const double &x);

int main()
{
	double m = 5;
	const double &r = m;
	cout << r;
	ref(m);
	cin.get();
}

void ref(const double &x)
{
	cout << x*x <<"d";
}

output:

5

could anyone tell me why?

[MrHutch]

I don't understand.

The output when I run this is as expected:

525d

[q1670741824]

what is your implementation? I use VC++ 2013

[MrHutch]

Compiled with gcc 4.7.1.

[q1670741824]

thank you!
But do you know why VC++ 2013 can't do that? do I need to set something?..

[mutexe]

i'm running VS2010 and also get

525d

[q1670741824]

and I finally find the problem, because ref is a class name or something in vc++ 2013, so i occationally use it. I changed the name then worked~