Recursive template problem

[Max Samukha]

On Wed, 30 Jul 2008 04:39:42 -0400, maelp <mael.primet at gmail.com>
wrote:

>I think what he looks for is not the actual result since his array of reals isn't const (not known at compile time), and he simply wants the actual *code* to be generated at compile time, so none of your solution will work. I've had similar problems of recursive template construction, so since there are several posts, maybe we'll have some answers.
>
>My problem was to construct a struct having k (known at compile time) elements named (for instance)
>v1 ... vk,
>
>ie. something like
>
>MyStruct!(5) 
>
>=>
>
>struct
>{
>  int v1, v2, v3, v4, v5 ;
>}
>
>someone could help me with this? Or is it possible to do this?
>
> 

One of a few ways to do that:

import std.stdio;
import std.metastrings;

template Fields(uint n)
{
    static if (n)
    {
        mixin ("int v" ~ ToString!(n) ~ ";");
        mixin Fields!(n - 1);
    }
}

struct S(uint n)
{
    mixin Fields!(n);
}

void main()
{
    S!(5) s;
    s.v1 = 1;
    s.v2 = 2;
    s.v5 = 3;    
}