Overriding to!string on enum types

[evilrat via Digitalmars-d-learn]

sorry, i forgot everything.
here is example of how to do this
-----

import std.conv : to;

enum Test
{
  One,
  Two,
  Three,
}


template to(T: string)
{
  T to(A: Test)(A val)
  {
   final switch (val)
   {
    case Test.One: return "1";
    case Test.Two: return "2";
    case Test.Three: return "3";
   }
  }
}


void main()
{
assert(to!string(Test.One) == "1");
auto t = cast(Test)2;
assert(to!string(t) == "3");
assert(to!int("4") == 4); // shows original to! template works
}