Re: Recursive template

[anonymous via Digitalmars-d-learn]

On Saturday, 15 November 2014 at 18:30:00 UTC, Eric wrote:

Hi -

I've never designed a recursive template before, but I think
that would solve my problem.  What I would like is
someting like this:

class X(V, K...)
{
    // I want to declare a type based on K and V such
    // that for X!(V, int, string, double) the resulting
    // declaration would be:
    SomeType!(int, SomeType!(string, SomeType!(double, V))) var;

    // or put another way:
    SomeType!(K[0], SomeType!(K[1], SomeType(K[2], V))) var;
}

Can anyone give me some ideas on how to set up the declaration?

Thanks,

Eric

It's pretty straight forward:

struct SomeType(K, V) {}

template X(V, K...)
{
     static if(K.length == 1)
         alias X = SomeType!(K[0], V);
     else static if(K.length > 1)
         alias X = SomeType!(K[0], X!(V, K[1 .. $]));
     else static assert(false);
}