https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81857
--- Comment #3 from Petr Ovtchenkov <abominable-snowman at yandex dot ru> --- Created attachment 42042 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42042&action=edit proposed test for issue https://gcc.gnu.org/ml/libstdc++/2017-08/msg00036.html May be worth to add (see issue2471) words to copy_n spec: "copy_n return result + n (i.e. increment OutputIterator n times) and increment InputIterator max(0, n - 1)." to avoid ambiguity?
