[Bug libstdc++/86138] [7/8 Regression] C++17: getline(istream, string) crashes on Cygwin because incompatible C++14 function is called

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86138

--- Comment #28 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Tue Aug  7 22:50:55 2018
New Revision: 263383

URL: https://gcc.gnu.org/viewcvs?rev=263383&root=gcc&view=rev
Log:
Declare some explicit instantiations for strings in Debug Mode

The empty reps and the I/O functions do not need to be implicitly
instantiated to enable assertions, so declare the explicit
instantiations when _GLIBCXX_EXTERN_TEMPLATE == -1 (i.e. when
_GLIBCXX_ASSERTIONS is defined).

Backport from mainline
2018-06-27  Jonathan Wakely  <jwak...@redhat.com>

        PR libstdc++/86138
        * include/bits/basic_string.tcc: [_GLIBCXX_EXTERN_TEMPLATE < 0]
        Declare explicit instantiations of COW empty reps and I/O functions.

Modified:
    branches/gcc-7-branch/libstdc++-v3/ChangeLog
    branches/gcc-7-branch/libstdc++-v3/include/bits/basic_string.tcc