Check if give an array is equal to first elements in another array

[MachineCode via Digitalmars-d-learn]

Is there one function in the Phobos library to check if give an 
array is equal to first elements in another array? e.g, f(a, b) 
the entire b array must match to first elements in a and then 
return true otherwise false, ie:

> a[0 .. b.length] == b

probably there's no such a function (but I wouldn't find bad if 
there was) in the D's library so what's a good name (that'a 
descriptive) to such a function?

btw, what it solves is:

> if(a.length >= b1.length && a[0 .. b1.length] == b1) { ... }
> if(a.length >= b2.length && a[0 .. b2.length] == b2) { ... }

since if bx.length < a.length is valid I can't remove all the 
a.length >= bx.length checks otherwise I can have a range 
violation error