Previously the iterators of boost::container::deque would assert when zero was added to them in at least the following situations:
The iterator was obtained by a call to boost::container::deque::begin and boost::container::deque::empty returns true
The iterator was default constructed
This is inconsistent with the way in which the iterators of boost::container::deque have behaved historically and is also inconsistent with an understanding of iterators developed by analogy with pointers:
Adding zero to a null pointer is valid despite the fact the null pointer cannot be dereferenced
Adding zero to a pointer that is one past the end yields a pointer which is still one past the end and thus which has well defined semantics
Fixed this issue and codified the expected behavior in unit tests.
igaztanaga
commented
4 years ago
Previously the iterators of
boost::container::dequewould assert when zero was added to them in at least the following situations:boost::container::deque::beginandboost::container::deque::emptyreturnstrueThis is inconsistent with the way in which the iterators of
boost::container::dequehave behaved historically and is also inconsistent with an understanding of iterators developed by analogy with pointers:Fixed this issue and codified the expected behavior in unit tests.