GitLab

	    Nathan C. Myers  <ncm-nospam@cantrip.org>

	PR libstdc++/11378
	* include/std/std_fstream.h (xsputn): Declare only.
	* include/bits/fstream.tcc (xsputn): Define, optimize for the
	always_noconv() case: when __n is sufficiently large flush
	the buffer and issue a direct write, if possible combining the
	two with writev in __basic_file<>::xsputn_2.
	* config/io/basic_file_stdio.h (__basic_file<>::xsputn_2):
	New, declare.
	* config/io/basic_file_stdio.cc (__basic_file<>::xsputn_2):
	Define.
	* acinclude.m4 (GLIBCXX_CHECK_WRITE): New macro, checking for
	the availability of writev in <sys/uio.h>.
	* configure.in: Call here.
	* acconfig.h: Add undef for the corresponding symbol.
	* aclocal.m4: Regenerate.
	* configure: Regenerate.
	* config.h.in: Regenerate.
	* testsuite/27_io/basic_filebuf/setbuf/char/3.cc: Tweak.

	* include/std/std_fstream.h (sync): Constify a variable.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@69341 138bc75d-0d04-0410-961f-82ee72b054a4