pythagoreanTriples

auto t = pythagoreanTriples!size_t;
alias Triple = typeof(t.front);
assert(t.front == Triple(1,1,2)); t.popFront();
assert(t.front == Triple(3,4,5)); t.popFront();
assert(t.front == Triple(6,8,10)); t.popFront();
assert(t.front == Triple(5,12,13)); t.popFront();
assert(t.front == Triple(9,12,15)); t.popFront();
assert(t.front == Triple(8,15,17)); t.popFront();
assert(t.front == Triple(12,16,20)); t.popFront();