The names of the vprint functions follow the convention from P3235R3.
This takes advantage of the additional permission proposed by P3107R5 so
that std::print can write directly to a FILE stream, rather than
formatting to an intermediate std::string temporary and then writing
that to the stream. The change is to write to a new _File_sink type
instead of a _Str_sink that populates a std::string. There are three
implementations of _File_sink.
For non-Glibc targets that support POSIX flockfile and putc_unlocked,
the stream will be locked and then formatted characters will be buffered
on the stack (instead of allocating a std::string) and copied to the
stream when the buffer fills up.
For Glibc, _File_sink will lock the stream but then if the file is
line-buffered or fully buffered, characters will be written directly
into the file's output buffer. This avoids two levels of buffering and
copying the characters from one to the other. For an unbuffered stream
(like stderr) the _File_sink buffer will still be used, to avoid the
overhead of lots of small writes to the stream. Because this version of
_File_sink accesses the stream's buffer directly it relies on
glibc-specific implementation details that are exposed in public
headers.
A fallback definition of _File_sink just wraps a _Str_sink so is
equivalent to the original code, and is used when flockfile isn't
available.
Both forms of std::println (taking a FILE* and a std::ostream) can be
implemented more efficiently by appending a newline to the format
string, to avoid formatting twice.
PR libstdc++/121790
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_CHECK_STDIO_LOCKING): New macro to check
for std::print dependencies.
* config.h.in: Regenerate.
* configure: Regenerate.
* configure.ac: Use GLIBCXX_CHECK_STDIO_LOCKING.
* include/bits/formatfwd.h (enable_nonlocking_formatter_optimization):
Define new variable template.
* include/bits/version.def (print): Bump value.
* include/bits/version.h: Regenerate.
* include/std/format (enable_nonlocking_formatter_optimization):
Define specializations for variable template.
* include/std/ostream (print) [!_WIN32]: Do not use
vprint_unicode at all.
(println): Append newline to format string instead of formatting
twice.
* include/std/print (_File_sink): New class.
(vprint_nonunicode_locking): New function.
(vprint_unicode_locking): New function reusing previous code
from vprint_unicode.
(vprintf_unicode): Defer to vprint_nonunicode for Windows or to
vprint_unicode_locking otherwise.
(print): [!_WIN32]: Do no use vprint_unicode at all.
Check enable_nonlocking_formatter_optimization and defer to
either vprint_nonunicode_locking or vprint_nonunicode.
(println): Use vprint_unicode or format directly to a _File_sink
instead of formatting twice.
* testsuite/27_io/print/1.cc: Updated and added new tests.
* testsuite/std/format/formatter/nonlocking.cc: New tests.
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Reviewed-by: Tomasz Kamiński <tkaminsk@redhat.com>
Co-authored-by: Tomasz Kamiński <tkaminsk@redhat.com>
The r16-142-g01e5ef3e8b9128 chagned return type of _Str_sink::view()
to basic_string_view<_CharT>. The mutable access is provided by _M_span
function, that is now used for mingw path.
PR libstdc++/119970
libstdc++-v3/ChangeLog:
* include/std/ostream (vprint_unicode) [_WIN32 && !__CYGWIN__]: Call
_Str_sink::_M_span instead of view.
* include/std/print (vprint_unicode) [_WIN32 && !__CYGWIN__]: Call
_Str_sink::_M_span instead of view.
This adds <bits/ostream.h> so that other headers don't need to include
all of <ostream>, which pulls in all of <format> since C++23 (for the
std::print and std::println overloads in <ostream>). This new header
allows the constrained operator<< in <bits/unique_ptr.h> to be defined
without all of std::format being compiled.
We could also replace <ostream> with <bits/ostream.h> in all of
<istream>, <fstream>, <sstream>, and <spanstream>. That seems more
likely to cause problems for users who might be expecting <sstream> to
define std::endl, for example. Although the standard doesn't guarantee
that, it is more reasonable than expecting <memory> to define it! We can
look into making those changes for GCC 16.
libstdc++-v3/ChangeLog:
PR libstdc++/99995
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/bits/unique_ptr.h: Include bits/ostream.h instead of
ostream.
* include/std/ostream: Include new header.
* include/bits/ostream.h: New file.
This was just approved in Wrocław.
libstdc++-v3/ChangeLog:
* include/std/ostream (println): Pass stream's locale to
std::format, as per LWG 4088.
* testsuite/27_io/basic_ostream/print/1.cc: Check std::println
with custom locale. Remove unused brit_punc class.
Some tests e.g. 17_intro/headers/c++1998/all_pedantic_errors.cc FAIL
with GLIBCXX_TESTSUITE_STDS=98 due to numerous C++11 extensions still in
use in the library headers. The recent changes to not make them system
headers means we get warnings now.
This change adds more diagnostic pragmas to suppress those warnings.
libstdc++-v3/ChangeLog:
* include/bits/istream.tcc: Add diagnostic pragmas around uses
of long long and extern template.
* include/bits/locale_facets.h: Likewise.
* include/bits/locale_facets.tcc: Likewise.
* include/bits/locale_facets_nonio.tcc: Likewise.
* include/bits/ostream.tcc: Likewise.
* include/bits/stl_algobase.h: Likewise.
* include/c_global/cstdlib: Likewise.
* include/ext/pb_ds/detail/resize_policy/hash_prime_size_policy_imp.hpp:
Likewise.
* include/ext/pointer.h: Likewise.
* include/ext/stdio_sync_filebuf.h: Likewise.
* include/std/istream: Likewise.
* include/std/ostream: Likewise.
* include/tr1/cmath: Likewise.
* include/tr1/type_traits: Likewise.
* include/tr1/functional_hash.h: Likewise. Remove semi-colons
at namespace scope that aren't needed after macro expansion.
* include/tr1/tuple: Remove semi-colon at namespace scope.
* include/bits/vector.tcc: Change LL suffix to just L.
LWG 117 specifies that inserting a float into an ostream should cast it
to double, because there's no std::num_put::put member that takes a
float. However, on RISC-V converting a NaN float to double loses the
sign, which means that negative NaN floats are printed as positive.
This has been reported as LWG 4101 and there is good support for fixing
the standard to preserve the sign bit when printing negative NaN values.
This change uses copysign((double)f, (double)std::bit_cast<int>(f)) to
get a double that preserves the sign. The bit_cast gives us an integer
with the same signbit, and casting that to the target type preserves
the signbit. We don't care about the value, as copysign only uses the
signbit.
The inserters for extended floating-point types need the same treatment,
so add a new _S_cast_flt helper to do the signbit-preserving conversion
generically.
So far only RISC-V has been confirmed to need this treatment, but we
might need to extend it to other targets later.
libstdc++-v3/ChangeLog:
PR libstdc++/113578
* include/std/ostream (_S_cast_flt): New static member function
to restore signbit after casting to double or long double.
(operator<<(float), operator<<(_Float16), operator<<(_Float32))
(operator<<(_Float64), operator(_Float128))
(operator<<(__bfloat16_t)): Use _S_cast_flt.
testsuite/27_io/basic_ostream/inserters_arithmetic/lwg4101.cc:
New test.
Co-authored-by: Andrew Waterman <andrew@sifive.com>
This questionable combination of flags causes a number of errors. The
ones in the rvalue stream overloads need to be fixed in the gcc-14
branch so I'm committing it separately to simplify backporting.
libstdc++-v3/ChangeLog:
PR libstdc++/116070
* include/std/istream: Check feature test macro before using
is_class_v and is_same_v.
* include/std/ostream: Likewise.
This was recently approved for C++26 at the Tokyo meeting. As suggested
by Stephan T. Lavavej, I'm defining it as an extension for C++23 mode
(when std::print and std::prinln were first added) rather than as a new
C++26 feature. Both MSVC and libc++ have agreed to do this too.
libstdc++-v3/ChangeLog:
* include/std/ostream (println(ostream&)): Define new overload.
* include/std/print (println(FILE*), println()): Likewise.
* testsuite/27_io/basic_ostream/print/2.cc: New test.
* testsuite/27_io/print/1.cc: Remove unused header.
* testsuite/27_io/print/3.cc: New test.
Cygwin should use std::fwrite, not WriteConsoleW. And the -lstdc++exp
library is only needed when running the tests on *-*-mingw*.
libstdc++-v3/ChangeLog:
* include/std/ostream (vprint_unicode) [__CYGWIN__]: Use POSIX
code path for Cygwin instead of Windows.
* include/std/print (vprint_unicode) [__CYGWIN__]: Likewise.
* testsuite/27_io/basic_ostream/print/1.cc: Only add -lstdc++exp
for *-*-mingw* targets.
* testsuite/27_io/print/1.cc: Likewise.
This change makes std::make_format_args refuse to create dangling
references to temporaries. This makes the std::vformat API safer. This
was approved in Kona 2023 as a DR for C++20 so the change is implemented
unconditionally.
libstdc++-v3/ChangeLog:
* include/bits/chrono_io.h (__formatter_chrono): Always use
lvalue arguments to make_format_args.
* include/std/format (make_format_args): Change parameter pack
from forwarding references to lvalue references. Remove use of
remove_reference_t which is now unnecessary.
(format_to, formatted_size): Remove incorrect forwarding of
arguments.
* include/std/ostream (print): Remove forwarding of arguments.
* include/std/print (print): Likewise.
* testsuite/20_util/duration/io.cc: Use lvalues as arguments to
make_format_args.
* testsuite/std/format/arguments/args.cc: Likewise.
* testsuite/std/format/arguments/lwg3810.cc: Likewise.
* testsuite/std/format/functions/format.cc: Likewise.
* testsuite/std/format/functions/vformat_to.cc: Likewise.
* testsuite/std/format/string.cc: Likewise.
* testsuite/std/time/day/io.cc: Likewise.
* testsuite/std/time/month/io.cc: Likewise.
* testsuite/std/time/weekday/io.cc: Likewise.
* testsuite/std/time/year/io.cc: Likewise.
* testsuite/std/time/year_month_day/io.cc: Likewise.
* testsuite/std/format/arguments/args_neg.cc: New test.
This implements the requirements in the following proposals, which
dictate how std::format deals with non-ASCII strings:
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1868r1.htmlhttps://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2572r1.htmlhttps://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2675r1.pdf
There are two parts to this. The width estimation for strings must only
count the width of the first character in an extended grapheme cluster.
That requires implementing the algorithm for detecting cluster breaks,
which requires a number of lookup tables of the grapheme cluster break
properties (and Indic_Conjunct_Break and Extended_Pictographic
properties) of every code point. Additionally, some characters have a
field width of 2, which requires another lookup table of field widths
for every code point. The tables added in this commit do not contain
entries for every code point from 0 to 0x10FFFF as that would be very
inefficient and use too much memory. Instead the tables only contain the
code points that form an "edge" for a property, omitting all the code
points that have the same property as the preceding one. We can use a
binary search to find the closest code point in the table that is not
greater than the one we're looking for.
The tables are generated by a new Python script added to the
contrib/unicode directory, and a new data file downloaded from the
Unicode Consortium website.
The rules for extended grapheme cluster breaking are implemented for the
latest Unicode standard, version 15.1.0.
libstdc++-v3/ChangeLog:
* include/Makefile.am: Add new headers.
* include/Makefile.in: Regenerate.
* include/bits/unicode.h: New file.
* include/bits/unicode-data.h: New file.
* include/std/format: Include <bits/unicode.h>.
(__literal_encoding_is_utf8): Move to <bits/unicode.h>.
(_Spec::_M_fill): Change type to char32_t.
(_Spec::_M_parse_fill_and_align): Read a Unicode scalar value
instead of a single character.
(__write_padded): Change __fill_char parameter to char32_t and
encode it into the output.
(__formatter_str::format): Use new __unicode::__field_width and
__unicode::__truncate functions.
* include/std/ostream: Adjust namespace qualification for
__literal_encoding_is_utf8.
* include/std/print: Likewise.
* src/c++23/print.cc: Add [[unlikely]] attribute to error path.
* testsuite/ext/unicode/view.cc: New test.
* testsuite/std/format/functions/format.cc: Add missing examples
from the standard demonstrating alignment with non-ASCII
characters. Add examples checking correct handling of extended
grapheme clusters.
contrib/ChangeLog:
* unicode/README: Add notes about generating libstdc++ tables.
* unicode/GraphemeBreakProperty.txt: New file.
* unicode/emoji-data.txt: New file.
* unicode/gen_libstdcxx_unicode_data.py: New file.
Since we don't need to do anything special to print Unicode on
non-Windows targets, we might as well just use std::vprint_nonunicode to
implement std::vprint_unicode. Removing the duplicated code should
reduce code size in cases where those calls aren't inlined.
Also use an RAII type for the unused case where a non-Windows target
calls __open_terminal(streambuf*) and needs to fclose the result. This
makes the code futureproof in case we ever start using the
__write_terminal function for non-Windows targets.
libstdc++-v3/ChangeLog:
* include/std/ostream (vprint_unicode) [_WIN32]: Use RAII guard.
(vprint_unicode) [!_WIN32]: Just call vprint_nonunicode.
* include/std/print (vprint_unicode) [!_WIN32]: Likewise.
Tim Song pointed out that although std::print behaves as a formatted
output function, it does "determine padding" using the stream's flags.
libstdc++-v3/ChangeLog:
* include/std/ostream (vprint_nonunicode, vprint_unicode): Do
not insert padding.
* testsuite/27_io/basic_ostream/print/1.cc: Adjust expected
behaviour.
This adds the C++23 std::print functions, which use std::format to write
to a FILE stream or std::ostream (defaulting to stdout).
The new extern symbols are in the libstdc++exp.a archive, so we aren't
committing to stable symbols in the DSO yet. There's a UTF-8 validating
and transcoding function added by this change. That can certainly be
optimized, but it's internal to libstdc++exp.a so can be tweaked later
at leisure.
Currently the external symbols work for all targets, but are only
actually used for Windows, where it's necessary to transcode to UTF-16
to write to the console. The standard seems to encourage us to also
diagnose invalid UTF-8 for non-Windows targets when writing to a
terminal (and only when writing to a terminal), but I'm reliably
informed that that wasn't the intent of the wording. Checking for
invalid UTF-8 sequences only needs to happen for Windows, which is good
as checking for a terminal requires a call to isatty, and on Linux that
uses an ioctl syscall, which would make std::print ten times slower!
Testing the std::print behaviour is difficult if it depends on whether
the output stream is connected to a Windows console or not, as we can't
(as far as I know) do that non-interactively in DejaGNU. One of the new
tests uses the internal __write_to_terminal function directly. That
allows us to verify its UTF-8 error handling on POSIX targets, even
though that's not actually used by std::print. For Windows, that
__write_to_terminal function transcodes to UTF-16 but then uses
WriteConsoleW which fails unless it really is writing to the console.
That means the 27_io/print/2.cc test FAILs on Windows. The UTF-16
transcoding has been manually tested using mingw-w64 and Wine, and
appears to work.
libstdc++-v3/ChangeLog:
PR libstdc++/107760
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/bits/version.def (__cpp_lib_print): Define.
* include/bits/version.h: Regenerate.
* include/std/format (__literal_encoding_is_utf8): New function.
(_Seq_sink::view()): New member function.
* include/std/ostream (vprintf_nonunicode, vprintf_unicode)
(print, println): New functions.
* include/std/print: New file.
* src/c++23/Makefile.am: Add new source file.
* src/c++23/Makefile.in: Regenerate.
* src/c++23/print.cc: New file.
* testsuite/27_io/basic_ostream/print/1.cc: New test.
* testsuite/27_io/print/1.cc: New test.
* testsuite/27_io/print/2.cc: New test.
We don't need any library concepts to define the constraints for rvalue
stream overloads, only compiler support. So change the test from using
__cpp_lib_concepts to __cpp_concepts >= 201907L.
libstdc++-v3/ChangeLog:
* include/std/istream (__rvalue_stream_extraction_t): Test
__cpp_concepts instead of __cpp_lib_concepts.
* include/std/ostream (__derived_from_ios_base): Likewise.
(__rvalue_stream_insertion_t): Likewise.
Update a preprocessor condition using __cplusplus and _GLIBCXX_HOSTED
to use the relevant feature test macro for <syncstream>.
Also add comments to some conditions saying which C++ standard revision
the check corresponds to.
libstdc++-v3/ChangeLog:
* include/std/atomic: Add comment to #ifdef and fix indentation.
* include/std/ostream: Check __glibcxx_syncbuf instead of
__cplusplus and _GLIBCXX_HOSTED.
* include/std/thread: Add comment to #ifdef.
The following patch adds the easy part of <charconv>, <istream> and
<ostream> changes for extended floats.
In particular, for the first one only overloads where the _Float* has
the same format as float/double/long double and for the latter two
everything but the _GLIBCXX_HAVE_FLOAT128_MATH case.
For charconv, I'm not really familiar with it, I'm pretty sure
we need new libstdc++.so.6 side implementation of from_chars for
{,b}float16_t and for to_chars not really sure but for unspecified precision
if it should emit minimum characters that to_chars then can unambiguously
parse, I think it is less than in the float case. For float128_t
{to,from}_chars I think we even have it on the library side already, just
ifdefed for powerpc64le only.
For i/o stream operator<</>>, not sure what is better, if not providing
anything at all, or doing what we in the end do if user doesn't override
the virtual functions, or use {to,from}_chars under the hood, something
else?
Besides this, the patch adds some further missed
// { dg-options "-std=gnu++2b" }
spots, I've also noticed I got the formatting wrong in some testcases
by not using spaces around VERIFY conditions and elsewhere by having
space before ( for calls.
The testsuite coverage is limited, I've added test for from_chars because
it was easy to port, but not really sure what to do about to_chars, it has
for float/double huge testcases which would be excessive to repeat.
And for i/ostream not really sure what exactly is worth testing.
2022-11-01 Jakub Jelinek <jakub@redhat.com>
* include/std/charconv (from_chars, to_chars): Add _Float{32,64,128}
overloads for cases where those types match {float,double,long double}.
* include/std/istream (basic_istream::operator>>): Add
_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t overloads.
* include/std/ostream (basic_ostream::operator<<): Add
_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t overloads.
* testsuite/20_util/from_chars/8.cc: New test.
* testsuite/26_numerics/headers/cmath/nextafter_c++23.cc (test):
Formatting fixes.
* testsuite/26_numerics/headers/cmath/functions_std_c++23.cc: Add
dg-options "-std=gnu++2b".
(test_functions, main): Formatting fixes.
* testsuite/26_numerics/headers/cmath/c99_classification_macros_c++23.cc:
Add dg-options "-std=gnu++2b".
On the libsdc++ mailing list Lewis Hyatt pointed out the performance
overhead of using sputn in stream inserters, rather than writing
directly to the streambuf's put area:
https://gcc.gnu.org/pipermail/libstdc++/2021-July/052877.html
As Lewis noted, the standard explicitly requires a call to sputn for
inserting a std::basic_string_view or std::basic_string. But for
inserting single characters or null-terminated strings it is more vague,
and so we can improve performance by not using the __ostream_insert
function.
This is a minimal change that avoids __ostream_insert for single
characters. We can use the unformatted basic_ostream::put(charT)
function when we don't need the additional effects of a formatted output
function (i.e. padding and resetting the width). The put function will
insert into the buffer if possible, and only make a virtual call (to
overflow) if the buffer is full.
We could also avoid sputn when inserting null-terminated character
strings, but that would require using a new function for inserting
null-terminated strings, so the existing code using sputn is still used
for basic_string and basic_string_view. My preference is to leave that
for now, and try to improve the standard. We could either remove the
requirement to call sputn, or allow sputn to write directly to the
buffer instead of calling xsputn.
libstdc++-v3/ChangeLog:
* include/std/ostream (operator<<(basic_ostream&, charT)):
Use unformatted input if no padding is needed.
(operator<<(basic_ostream<char>&, char)): Likewise.
We don't need to have <wchar.h> support in order to delete overloads
for inserting wide characters into narrow streams.
libstdc++-v3/ChangeLog:
PR libstdc++/98725
* include/std/ostream (operator<<(basic_ostream<char, Tr>&, wchar_t))
(operator<<(basic_ostream<char, Tr>&, const wchar_t*)): Always
define as deleted. Do not check _GLIBCXX_USE_WCHAR_T.
To avoid needing to export a new symbol from the library (for now) the
new member function uses __attribute__((always_inline)).
libstdc++-v3/ChangeLog:
* include/std/ostream (operator<<(const volatile void*)):
Add new overload, as per P1147R1.
* testsuite/27_io/basic_ostream/inserters_other/char/volatile_ptr.cc:
New test.
Currently if ostream::write fails and sets badbit and that causes an
exception, we will catch the exception, set badbit again, and rethrow
the exception.
This change delays setting badbit until after the try-catch block, so
that if it causes an exception we don't need to catch and rethrow it.
This removes the last remaining use of _M_write, so it can be made
private (or removed entirely for versioned namespace builds, where ABI
compatibility is not required). All other uses of _M_write were replaced
by calls to __ostream_insert, so make _M_write use that too.
libstdc++-v3/ChangeLog:
* include/bits/ostream.tcc (basic_ostream::write): Call sputn
directly instead of using _M_write. Do setstate(__err) all
outside the try-catch block.
* include/std/ostream (basic_ostream::_M_write): Declare
private. Use __ostream_insert. Do not define for the versioned
namespace.
The __rval_streamable() function was an attempt to test for
convertibility cheaply and without confusing diagnostics. It doesn't
work with Clang though, and is probably ill-formed.
Replace that helper function with a check for derivation from ios_base,
and use that in the alias templates __rvalue_stream_insertion_t and
__rvalue_stream_extraction_t. Use concepts for the constraints when
available.
libstdc++-v3/ChangeLog:
* include/std/istream (__rvalue_stream_extraction_t): Replace
use of __rval_streamable.
* include/std/ostream (__rvalue_stream_insertion_t): Likewise.
(__rval_streamable): Remove.
(_Require_derived_from_ios_base, __derived_from_ios_base): New
helper for checking constraints.
* testsuite/27_io/basic_istream/extractors_other/char/4.cc: Fix
reference to the wrong subclause of the standard.
* testsuite/27_io/basic_istream/extractors_other/wchar_t/4.cc:
Likewise.
* testsuite/27_io/basic_ostream/inserters_other/char/6.cc:
Likewise.
* testsuite/27_io/basic_ostream/inserters_other/wchar_t/6.cc:
Likewise.
* testsuite/27_io/basic_ostream/inserters_other/char/99692.cc:
New test.
* testsuite/27_io/filesystem/path/io/dr2989.cc: Adjust pruned
errors.
This implements the resolution of LWG 1203 so that the constraints for
rvalue stream insertion/extraction are simpler, and the return type is
the original rvalue stream type not its base class.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/istream (operator>>(Istream&&, x&)): Simplify, as
per LWG 1203.
* include/std/ostream (operator<<(Ostream&&, const x&)):
Likewise.
* testsuite/27_io/basic_istream/extractors_character/char/lwg2499_neg.cc:
Adjust dg-error pattern.
* testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499_neg.cc:
Likewise.
* testsuite/27_io/basic_istream/extractors_other/char/4.cc: Define
is_extractable trait to replace std::__is_extractable. Make it
work with rvalue streams as well as lvalues, to replace f() and
g() helper functions.
* testsuite/27_io/basic_istream/extractors_other/wchar_t/4.cc:
Likewise.
* testsuite/27_io/basic_ostream/inserters_other/char/6.cc:
Define is_insertable trait to replace std::__is_insertable. Make
it work with rvalue streams as well as lvalues, to replace f()
and g() helper functions.
* testsuite/27_io/basic_ostream/inserters_other/wchar_t/6.cc:
Likewise.
* testsuite/27_io/filesystem/path/io/dr2989.cc: Prune additional
errors from new constraints.
* testsuite/27_io/rvalue_streams-2.cc: Remove PR 80675 checks,
which are no longer expected to compile.
* testsuite/27_io/rvalue_streams.cc: Adjust existing test.
Verify LWG 1203 changes.
This adds the manipulators for use with basic_osyncstream. In order to
detect when an arbitrary basic_ostream<C,T> is the base class of a
basic_syncbuf<C,T,A> object, introduce a new intermediate base class
that stores the data members. The new base class stores a pointer and
two bools, which wastes (sizeof(void*) - 2) bytes of padding. It would
be possible to use the two least significant bits of the pointer for the
two bools, at least for targets where alignof(basic_streambuf) > 2, but
that's left as a possible change for a future date.
Also define basic_syncbuf::overflow to override the virtual function in
the base class, so that single characters can be inserted into the
stream buffer. Previously the default basic_streambuf::overflow
implementation was used, which drops the character on the floor.
libstdc++-v3/ChangeLog:
* include/std/ostream (__syncbuf_base): New class template.
(emit_on_flush, noemit_on_flush, flush_emit): New manipulators.
* include/std/syncstream (basic_syncbuf): Derive from
__syncbuf_base instead of basic_streambuf.
(basic_syncbuf::operator=): Remove self-assignment check.
(basic_syncbuf::swap): Remove self-swap check.
(basic_syncbuf::emit): Do not skip pubsync() call if sequence
is empty.
(basic_syncbuf::sync): Remove no-op pubsync on stringbuf.
(basic_syncbuf::overflow): Define override.
* testsuite/27_io/basic_syncstream/basic_ops/1.cc: Test
basic_osyncstream::put(char_type).
* testsuite/27_io/basic_ostream/emit/1.cc: New test.
Update feature test macro, add deleted operators, update u8path
This patch increments the __cpp_lib_char8_t feature test macro, adds deleted
operator<< overloads for basic_ostream, and modifies u8path to accept
sequences of char8_t for both the C++17 implementation of std::filesystem, and
the filesystem TS implementation.
The implementation mechanism used for u8path differs between the C++17 and
filesystem TS implementations. The changes to the former take advantage of
C++17 'if constexpr'. The changes to the latter retain C++11 compatibility
and rely on tag dispatching.
2019-11-29 Tom Honermann <tom@honermann.net>
Update feature test macro, add deleted operators, update u8path
* include/bits/c++config: Bumped the value of the __cpp_lib_char8_t
feature test macro.
* include/bits/fs_path.h (u8path): Modified u8path to accept sequences
of char8_t.
* include/experimental/bits/fs_path.h (u8path): Modified u8path to
accept sequences of char8_t.
* include/std/ostream: Added deleted overloads of wchar_t, char8_t,
char16_t, and char32_t for ordinary and wide formatted character and
string inserters.
From-SVN: r278856
2019-01-10 Ville Voutilainen <ville.voutilainen@gmail.com>
Jonathan Wakely <jwakely@redhat.com>
Implement LWG 2221
* config/abi/pre/gnu.ver (GLIBCXX_3.4): Tighten patterns.
(GLIBCXX_3.4.26): Add new exports.
* include/Makefile.am: Add ostream-inst.cc. Move string-inst.cc to
correct list of sources.
* include/Makefile.in: Regenerate.
* include/std/ostream (operator<<(nullptr_t)): New member function.
* src/c++17/ostream-inst.cc: New file.
* testsuite/27_io/basic_ostream/inserters_other/char/lwg2221.cc: New
test.
Co-Authored-By: Jonathan Wakely <jwakely@redhat.com>
From-SVN: r267808
C++17 says to use std::uncaught_exceptions() here instead of
std::uncaught_exception() but since we only care whether the result is
non-zero (and we aren't planning to remove the deprecated version) we
can just keep using std::uncaught_exception() and suppress the warning.
* include/std/ostream (basic_ostream::sentry::~sentry): Suppress
deprecation warnings for using uncaught_exception().
From-SVN: r263593
* include/std/istream:
(__is_convertible_to_basic_istream_test(basic_istream<_Ch, _Up>*)): New.
(__do_is_convertible_to_basic_istream_impl): Likewise.
(__is_convertible_to_basic_istream_impl): Likewise.
(__is_convertible_to_basic_istream): Use the new base.
(__rvalue_istream_type): New.
(operator>>(_Istream&&, _Tp&&)): Use the new helper alias
for the SFINAE check, convert to the helper alias type before
doing the actual extraction.
* include/std/ostream:
(__is_convertible_to_basic_ostream_test(basic_ostream<_Ch, _Up>*)): New.
(__do_is_convertible_to_basic_ostream_impl): Likewise.
(__is_convertible_to_basic_ostream_impl): Likewise.
(__is_convertible_to_basic_ostream): Use the new base.
(__rvalue_ostream_type): New.
(operator<<(_Ostream&&, const _Tp&)): Use the new helper alias
for the SFINAE check, convert to the helper alias type before
doing the actual insertion.
* testsuite/27_io/rvalue_streams-2.cc: Add new tests.
From-SVN: r249468
The convertible_to traits need to use a variadic catch-all for the
false-cases.
* include/std/istream (__is_convertible_to_basic_istream):
Change the parameter of the false-case of __check to a variadic.
* include/std/ostream (__is_convertible_to_basic_ostream):
Likewise.
From-SVN: r243098
* include/std/istream (__is_convertible_to_basic_istream):
Change the return types of __check, introduce istream_type.
(operator>>(_Istream&&, _Tp&&)):
Use __is_convertible_to_basic_istream::istream_type as the return type.
* include/std/ostream (__is_convertible_to_basic_ostream):
Change the return types of __check, introduce ostream_type.
(operator>>(_Ostream&&, _Tp&&)):
Use __is_convertible_to_basic_ostream::ostream_type as the return type.
From-SVN: r243036
Jakub Jelinek