How to implement predicates for Filter!(Pred, Tuple)

[Tobias Pankrath]

I've written a Filter-Template, which implements the well-known function for
template arguments:

-----
template Filter(alias SPred, E...)
{
    static if(E.length == 0) {
        alias TypeTuple!() Filter;
    }
    else
    {
        static if(SPred!(E[0]))
        {
            alias TypeTuple!(E[0], Filter!(SPred, E[1..$])) Filter;
        }
        else
        {
            alias Filter!(SPred, E[1..$]) Filter;
        }
    }
}
------

This works just fine:
---
template IsEqual(int This)
{
    template IsEqual(int That)
    {
        enum bool IsEqual = This == That;
    }
}

static assert(is(Filter!(IsEqual!5, 5,1,5,1,5) == TypeTuple!(5, 5, 5)));
---

However I can't use it directly, for example like this:
> pragma(msg, IsEqual!(5)!5);

However if I wouldn't rely on the ETT, and use a different name for the 
inner 
template, it will work.

---
template IsEqual(int This)
{
  template Pred(int That)
  {
    enum bool Pred = This == That;
  }
}

pragma(msg, IsEqual!(5).Pred!(5));
---

But that will make IsEqual less elegant to use in conjunction with filter. 
So, is there a way to elegantly use one template in both cases? Otherwise I 
would declare two versions:
one with a single and one with two parameter.

--
Tobias