[Bug libstdc++/105284] missing syncstream and spanstream forward decl. in <iosfwd>

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105284

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jonathan Wakely
<redi@gcc.gnu.org>:

https://gcc.gnu.org/g:1572e41d759950e7699d14779aae49b892f12f8b

commit r11-9977-g1572e41d759950e7699d14779aae49b892f12f8b
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue May 10 13:03:14 2022 +0100

    libstdc++: Add <syncstream> declarations to <iosfwd> [PR105284]

    libstdc++-v3/ChangeLog:

            PR libstdc++/105284
            * include/std/iosfwd: Add declarations for <synstream> class
            templates and typedefs.
            * include/std/syncstream (basic_syncbuf, basic_osyncstream):
            Remove default template arguments.
            * testsuite/27_io/headers/iosfwd/synopsis.cc: New test.
            * testsuite/27_io/headers/iosfwd/types.cc: New test.

    (cherry picked from commit 1807e07825a86916bbfddca470708c5a8f613612)