+
+ if (Traits::stopLess(posA.stop(), posB.start())) {
+ // A ends before B begins. Catch up.
+ posA.advanceTo(posB.start());
+ if (!posA.valid() || !Traits::stopLess(posB.stop(), posA.start()))
+ return;
+ } else if (Traits::stopLess(posB.stop(), posA.start())) {
+ // B ends before A begins. Catch up.
+ posB.advanceTo(posA.start());
+ if (!posB.valid() || !Traits::stopLess(posA.stop(), posB.start()))
+ return;
+ } else
+ // Already overlapping.
+ return;
+