Base interfaces tuple

[Jarrett Billingsley]

"John C" <johnch_atms at hotmail.com> wrote in message 
news:frgcqg$10kl$1 at digitalmars.com...

> BaseTypeTuple from std.traits seems to be the starting point, and 
> recursively calling that template gets successive base types, but putting 
> that together into a single template has defeated me. Anyone accomplished 
> this?

Here's a Tango-y version:

import tango.core.Traits;

template AllBasesImpl(T...)
{
  static if(T.length == 0)
    alias Tuple!() AllBasesImpl;
  else
    alias Tuple!(T[0], AllBasesImpl!(BaseTypeTupleOf!(T[0])), 
AllBasesImpl!(T[1 .. $])) AllBasesImpl;
}

template AllBases(T)
{
  alias Unique!(AllBasesImpl!(BaseTypeTupleOf!(T))) AllBases;
}

I believe the Phobos version would be something like this:

import std.typetuple;
import std.traits;

template AllBasesImpl(T...)
{
  static if(T.length == 0)
    alias TypeTuple!() AllBasesImpl;
  else
    alias TypeTuple!(T[0], AllBasesImpl!(BaseTypeTuple!(T[0])), 
AllBasesImpl!(T[1 .. $])) AllBasesImpl;
}

template AllBases(T)
{
  alias NoDuplicates!(AllBasesImpl!(BaseTypeTuple!(T))) AllBases;
}