return type and templates

[Andrea Fontana]

I've seen many different topic about this, but they don't explain 
what's wrong with this "proposed" feature. Who can explain me why 
this can't be added to language? Does it broke something?

// Trivial example:

struct Test
{
	@property
	auto value(T)() if (is(T == int)) { return _intValue; }

	@property
	void value(T)(T val) if (is(T == int)) { _intValue = val; }

	private int _intValue;
}

void main()
{
	Test s;
	s.value!int(3); // Works

	s.value(3); // Works, magic
	s.value = 3; // Works, magic

	int t1 = s.value!int; // Works
	auto t2 = s.value!int; // Works

	auto t4 = s.value; // Doesn't work (and i don't think it should)
	int t3 = s.value; // <--Doesn't work (can this feature be 
implemented?)
	
}