const(Object)ref is here!

[Michel Fortin]

On 2010-12-06 14:46:51 -0500, spir <denis.spir at gmail.com> said:

> On Mon, 6 Dec 2010 13:44:41 -0500
> Michel Fortin <michel.fortin at michelf.com> wrote:
> 
>> Since we're speaking of the optional use of 'ref', here's a little quiz:
>> 
>> 	alias Object A;
>> 	alias Object ref B;
>> 
>> 	A ref a;
>> 	B ref b;
>> 
>> What happens here? Should there be an error somewhere? Where? Also,
>> what happens if we apply different modifiers at different places?
> 
> As I understand the (non-)semantics of 'ref', there should be no error. Thi
> s code should considered by the compiler as equivalent to:
> 	Object a;
> 	Object b;

And that's what my patch does. It only gets confusing when you add modifiers:

	alias const(Object)ref A;
	alias const(Object ref) B;
	alias const(Object) C;

	A ref a;
	B ref b;
	C ref c;

With my patch, variables 'a', 'b', and 'c' are all of the same type: 
"const(Object)ref", the later 'ref' changing the constness of the 
reference specified in the 'B' alias.

Note that while this behaviour is allowed with an alias, it is *not* 
allowed directly, so you can't write this for instance:

	const(Object ref) ref d;

That's an error.


-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/