No static fold in phobos ?

[userabcABC123 via Digitalmars-d-learn]

That would work on an AliasSeq ?
I'm surprised not to find one:

eg:

~~~~~~~
enum seq = AliasSeq!("aa", "bb");
enum val = staticFold!((a,b)=>a~b, seq);
static assert(val == "aabb");
~~~~~~~

it works with foreach or a eponymous template that consumes the 
sequence , but as said where is it in phobos ?