Partial template function specialization

[Bill Baxter]

On Thu, Aug 20, 2009 at 7:22 AM, Peter
Alexander<peter.alexander.au at gmail.com> wrote:
> Lars T. Kyllingstad Wrote:
>
>> Disclaimer: You didn't say whether you use D1 or D2, but I use D2, so
>> I'll give my answer in D2 code. It is highly likely it will also work in D1.
>
> I'm using neither :)  I'm just considering learning at the moment.
>
>
>> First of all, I don't know how it is in C++, but in D you rarely write
>> function declarations without definitions. So unless you have a very
>> general function body for your "general case", I'd simply drop it. If
>> you have, the general case looks like this:
>>
>>  <snip>
>>
>> For more info, check out http://www.digitalmars.com/d/2.0/template.html
>>
>> -Lars
>
> Excellent! Thanks a lot. I was hoping that D could overcome this problem.
>
>
> Ah, one (maybe) final question:
>
> Is there an equivalent to friends in D (didn't see any in the docs)? If so, do they work with templates easily?
>
> In my style of programming, I very rarely use member functions (I think they are an atrocity in language design), so I create global functions for almost everything, and when they need to access to private members, I have the class declare the function as a friend.
>
> Does D support my style of programming?

Instead of friend, in D everything within one file (==one module) has
access to everything else in that same file/module.

So you can use your style, as long as you put the global functions in
the same module as the classes operated on.

> Here's a concrete example of something I'd like to do (pseudocode):
>
> class Foo { private int x; friend globalFun; }
> class Bar { private int y; friend globalFun; }
>
> void globalFun(ref Foo foo, ref Bar bar) { foo.x = bar.y; }
>
> Is there anything like this in D? Export sounds like the right thing, but can that be used in the example above, assuming that Foo and Bar are in separate modules?

I don't think export has anything to do with it.

--bb