Current assign() implementation from iterator pairs is broken for single-pass iterators (https://en.cppreference.com/w/cpp/iterator/input_iterator) since it assumes that the iterators satisfy at least the forward-iterator requirements (w/o checking those).
Boost.Container, at least sequence containers, should support "assign" from input iterators and that is tested in the library tests. Do you have an example that can reproduce the problem?
Current assign() implementation from iterator pairs is broken for single-pass iterators (https://en.cppreference.com/w/cpp/iterator/input_iterator) since it assumes that the iterators satisfy at least the forward-iterator requirements (w/o checking those).