Region.includes

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

R emptyRegion;
auto region = R([TI(0, 0, 10), TI(1, 0, 10)]);

assert(TP(0, 0) !in emptyRegion);
assert(TP(0, 5) !in emptyRegion);
assert(TP(0, 10) !in emptyRegion);
assert(TP(0, 20) !in emptyRegion);
assert(TP(0, 0) in region);
assert(TP(0, 5) in region);
assert(TP(0, 10) !in region);
assert(TP(0, 20) !in region);
assert(TP(1, 0) in region);
assert(TP(1, 5) in region);
assert(TP(1, 10) !in region);
assert(TP(1, 20) !in region);