The definition of templates in D

[FeepingCreature]

On 03/18/12 11:29, Derek wrote:
> On Sun, 18 Mar 2012 19:16:02 +1100, Andrej Mitrovic <andrej.mitrovich at gmail.com> wrote:
> 
>> On 3/18/12, Derek <ddparnell at bigpond.com> wrote:
>>> What would be useful is ...
>>>   bar!(a, b, c); // is equivalent to
>>>   bar!(int, int, int).bar(a, b, c);
>>
>> You mean like this?
>>
>> template bar(T...)
>> {
>>     void bar() { writeln(T); }
>> }
>>
>> void main()
>> {
>>     int a = 1, b = 2, c = 3;
>>     bar!(a, b, c);
>> }
> 
> Almost, but more like this ...
> 
> template add(X,Y,Z)
> {
>    X add(Y a, Z b)
>    {
>        return cast(X) (cast(X)a + cast(X)b);
>    }
> }
> 
> void main()
> {
>      double s;
>      int   t;
>      ulong u;
> 
>      s = 1.23;
>      t = 123;
>      u = 456;
> 
>     t = add!(u,s);
> 
>     writefln( "%s %s %s", s,t, u );
> }
> 
> 
> 
> This currently errors with ...
> 
>   "Error: template instance add!(u,s) add!(u,s) does not match template declaration add(X,Y,Z)"
> 
why would you do that

what do you want to _do_

it sounds like you're frantically trying to nail templates into a shape that they really really really aren't meant for

in any case what is wrong with auto add(T)(T t) { return t[0] + t[1]; }