[Bug c++/58191] Can't use boost transform_iterator with _GLIBCXX_DEBUG

["daniel.kruegler at googlemail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58191

--- Comment #3 from Daniel KrÃgler <daniel.kruegler at googlemail dot com> ---
First, this issue should be categorized as belonging to the component
"libstdc++", not to "c++".

Second, the defect report is invalid, because std::upper_bound requires a
minimum iterator category of "forward iterator", but boost::transform_iterator
with a function object that returns a value (not a real reference) has an
iterator category "input iterator", which is correct, since forward iterators
are required to return a real reference for operator*.