Multiple range enumeration

[puming via Digitalmars-d-learn]

Hi,

If I have multiple ranges, say:
auto a = [1, 2, 3];
auto b = ["a", "b", "c"];
auto c = ["x", "y", "z"];

I'd like a composition range that enumerate all combinations of 
these ranges,
having the same effect as a nested foreach loop:

foreach (i; a) {
  foreach (j; b) {
    foreach (k; c) {
       writlen(i, j, k);
    }
  }
}

Is there such a generic function in std lib?