Function comb
Create a Comb struct from a range or of a set of bounds.
auto auto comb(T)
(
T stuff,
uint r
);
Examples
auto c1 = comb([1,2,3], 2); // Any two elements from [1,2,3].
auto c2 = comb(5, 3); // Any three elements from [0,1,2,3,4].