How to test templates for equality?

[Rene Zwanenburg via Digitalmars-d-learn]

On Tuesday, 1 July 2014 at 05:58:19 UTC, Uranuz wrote:
> Thanks for quick response. I really forget to look into 
> language __traits statement.

Another option:

enum isFoo(T) = is(T == Foo!P, P...);

By using such an is-expression you get the parameters Foo was 
instantiated with as an added bonus.

struct Foo(T)
{
	T val;	
}

auto createAFoo(T)(string s)
if(is(T == Foo!P, P))
{
	return T(s.to!P);
}