TaggedInterval.opBinary

alias R = Region!(int, int);
alias TI = R.TaggedInterval;

assert(TI(0, 10, 20) - TI(0, 0, 5) == R([TI(0, 10, 20)]));
assert(TI(0, 10, 20) - TI(0, 5, 15) == R([TI(0, 15, 20)]));
assert(TI(0, 10, 20) - TI(0, 12, 18) == R([TI(0, 10, 12), TI(0, 18, 20)]));
assert(TI(0, 10, 20) - TI(0, 10, 20) == R([]));
assert(TI(0, 10, 20) - TI(0, 15, 25) == R([TI(0, 10, 15)]));
assert(TI(0, 10, 20) - TI(0, 25, 30) == R([TI(0, 10, 20)]));
assert(TI(0, 10, 20) - TI(1, 25, 30) == R([TI(0, 10, 20)]));