[Bug libstdc++/59042] Declaration of back_insert_iterator::value_type is incorrect

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59042

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
And in [back.insert.iterator] the standard explicitly requires this:

template <class Container>
class back_insert_iterator :
public iterator<output_iterator_tag,void,void,void,void>{