Annex C (informative) Compatibility [diff]

C.1 C++ and ISO C++ 2017 [diff.cpp17]

C.1.11 [containers]: containers library [diff.cpp17.containers]

Affected subclauses: [forward.list] and [list]
Change: Return types of remove, remove_­if, and unique changed from void to container​::​size_­type.

Rationale: Improve efficiency and convenience of finding number of removed elements.

Effect on original feature: Code that depends on the return types might have different semantics in this revision of C++.
Translation units compiled against this version of C++ may be incompatible with translation units compiled against C++ 2017, either failing to link or having undefined behavior.