UFCS for D

[Steven Schveighoffer]

On Fri, 30 Mar 2012 20:25:10 -0400, Walter Bright  
<newshound2 at digitalmars.com> wrote:

> On 3/30/2012 12:36 PM, Walter Bright wrote:
>> On 3/30/2012 12:11 PM, Steven Schveighoffer wrote:
>>> On Fri, 30 Mar 2012 14:27:43 -0400, Walter Bright  
>>> <newshound2 at digitalmars.com>
>>> wrote:
>>>
>>>>
>>>> I would argue that:
>>>>
>>>> 3. An extension method for an argument of type template parameter T  
>>>> will be
>>>> looked up only in the instantiation scope.
>>>
>>> I don't think you looked at my counter case in detail. Your idea leads  
>>> to two
>>> different instantiations of tmpl!Foo having two different  
>>> implementations,
>>> depending on which extension methods you include. In fact, in one  
>>> place, the
>>> instantiation might succeed, but in another, the instantiation might  
>>> fail.
>>
>> Yes, you're right. I missed that nuance. I don't really know how to fix  
>> it.
>
> Ah, I know how to fix it. Mark such instantiations as "local" ones, so  
> they are mangled with the module name of where they were instantiated  
> from.

As I mentioned, this is the horrible solution I did not wish to have :(

What is wrong with my proposal (item 2 from my original post)?  It seems  
like it would be as easy to implement as your proposal, and does not  
create "local" instantiations.

-Steve