[Bug libstdc++/81912] std::distance not constexpr in C++17 mode

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81912

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Mon Sep  4 12:24:53 2017
New Revision: 251657

URL: https://gcc.gnu.org/viewcvs?rev=251657&root=gcc&view=rev
Log:
PR libstdc++/81912 make std::__iterator_category constexpr

Backport from mainline
2017-08-21  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/81912
        * include/bits/stl_iterator_base_types.h (__iterator_category): Add
        constexpr for C++11 and later.
        * testsuite/24_iterators/container_access.cc: Add target selector.
        * testsuite/24_iterators/range_access.cc: Fix clause number in
        comment.
        * testsuite/24_iterators/range_access_cpp14.cc: Likewise.
        * testsuite/24_iterators/range_access_cpp17.cc: New.

Added:
   
branches/gcc-7-branch/libstdc++-v3/testsuite/24_iterators/range_access_cpp17.cc
Modified:
    branches/gcc-7-branch/libstdc++-v3/ChangeLog
    branches/gcc-7-branch/libstdc++-v3/include/bits/stl_iterator_base_types.h
   
branches/gcc-7-branch/libstdc++-v3/testsuite/24_iterators/container_access.cc
    branches/gcc-7-branch/libstdc++-v3/testsuite/24_iterators/range_access.cc
   
branches/gcc-7-branch/libstdc++-v3/testsuite/24_iterators/range_access_cpp14.cc