Index a parameter tuple with a run-time index

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On Friday, 15 January 2016 at 20:48:39 UTC, anonymous wrote:
> On 15.01.2016 21:42, Nordlöw wrote:
>> How do I index a function parameter tuple with a run-time 
>> index?
>
> With a switch and a static foreach:
>
> ----
> void f(A...)(size_t i, A a)
> {
>     import std.stdio: writeln;
>     switch_: switch (i)
>     {
>         foreach (iT, T; A)
>         {
>             case iT: writeln(T.stringof); break switch_;
>         }
>         default: writeln("??"); break;
>     }
> }
>
> void main()
> {
>     f(0, "foo", 42); /* string */
>     f(1, "foo", 42); /* int */
>     f(2, "foo", 42); /* ?? */
> }
> ----

And of course I'm proven wrong as soon as I post :) Sometimes I 
forget how powerful D's  code generation abilities are.