Just one more thing...

[Max Samukha]

On Tue, 03 Mar 2009 20:05:28 +1100, Daniel Keep
<daniel.keep.lists at gmail.com> wrote:

>
>
>Bill Baxter wrote:
>> On Mon, Mar 2, 2009 at 11:55 AM, Daniel Keep
>> <daniel.keep.lists at gmail.com> wrote:
>>>
>>> Frits van Bommel wrote:
>>>> Sean Kelly wrote:
>>>>> Daniel Keep wrote:
>>>>>> extern(C) void __identifier("blah$UNIX2003")(int);
>>>>> That would be awesome.
>>>>>
>>>>>> A beneficial side-effect is that I can finally get rid of all those
>>>>>> mixins that are just doing this:
>>>>>>
>>>>>> mixin(`void `~name_of_fn~`(int a)
>>>>>> {
>>>>>>     // ... rest of function ...
>>>>>> }`);
>> 
>> I'm sure you've thought of this, so why can you not do
>>    mixin(`void `~name_of_fn~`(int a) { implementation_of_function(a); }`);
>> or
>>    mixin(`alias implementation_of_function `~name_of_fn~`);
>
>Simple enough to break:
>
>mixin(Property("foo", int));
>mixin(Property("bar", float));
>
>You can't use alias.  You have to have some way of generating unique
>symbol names in a context you don't have any control over. 

As of 1.039, it seems to be possible to generate unique symbols in a
reasonable way (not well tested):

template UniqueAlias(string member, string idName, int id = 0)
{
    static if (is(typeof(mixin("this." ~ idName ~ ToString!(id)))))
        mixin UniqueAlias!(member, idName, id + 1);
    else
        mixin("alias " ~ member ~ " " ~ idName ~ ToString!(id) ~ ";");
}

unittest
{
    class A
    {
        int x;
    }
    
    class B : A
    {
        int y;
        void foo() {}
            
        template Bar() {}

        mixin UniqueAlias!("x", "m");
        mixin UniqueAlias!("y", "m");
        mixin UniqueAlias!("x", "m");
        mixin UniqueAlias!("foo", "m");
        mixin UniqueAlias!("Bar", "m");
    }

    auto s = new B;
    s.m0 = 1;
    s.m1 = 2;
    assert(s.x == 1);
    assert(s.y == 2);
    assert(s.m2 == 1);
    s.m3();   
    alias B.m4!() bar;
}

>There are also little issues with this like how the name of the function, when
>debugging, won't be what you expect it to be.
>
>No, you can't use templates because you can't mixin functions with
>non-public protection with templates.
>
>  -- Daniel