Fallback 'catch-all' template functions

[Manu via Digitalmars-d]

So, consider a set of overloads:

  void f(T)(T t) if(isSomething!T) {}
  void f(T)(T t) if(isSomethingElse!T) {}
  void f(T)(T t) {}

I have a recurring problem where I need a fallback function like the
bottom one, which should be used in lieu of a more precise match.
This is obviously an ambiguous call, but this is a pattern that comes
up an awful lot. How to do it in D?

I've asked this before, and people say:

  void f(T)(T t) if(!isSomething!T && !isSomethingElse!T) {}

Consider that more overloads are being introduced by users spread out
across many modules that define their own kind of T; this solution is
no good.