This was recently approved for C++26.
We should define the __cpp_lib_freestanding_cstring macro in <string.h>
as well as <cstring>, but we do not currently install our own <string.h>
for most targets.
libstdc++-v3/ChangeLog:
* include/bits/version.def (freestanding_cstring): Add.
* include/bits/version.h: Regenerate.
* include/c_compatibility/string.h (strtok): Do not declare for
C++26 freestanding.
* include/c_global/cstring (strtok): Likewise.
* testsuite/21_strings/headers/cstring/version.cc: New test.
As well as the _GLIBCXX_USE_C99_STDLIB check, we also have a separate
check in linkage.m4 for just strtof and strtold. We can use that to
declare std::strtof and std::strtold in <cstdlib> for additional
targets. That allows us to enable std::stold on hpux11.11 which is
missing strtoll, strtoull and strtof, so doesn't define
_GLIBCXX_USE_C99_STDLIB. Although it doesn't help hpux11.11, we can
define std::stof for more targets this way too.
As with the previous commit for PR110653, this only affects the narrow
character overloads. std::stof and std::stold for wstring still requires
C99 <wchar.h> support.
libstdc++-v3/ChangeLog:
PR libstdc++/110653
* include/bits/basic_string.h [_GLIBCXX_HAVE_STRTOF] (stof):
Define.
[_GLIBCXX_HAVE_STRTOLD] (stold): Define.
* include/c_global/cstdlib [_GLIBCXX_HAVE_STRTOF] (strtof):
Declare in namespace std.
[_GLIBCXX_HAVE_STRTOLD] (strtold): Likewise.
This should make it possible to use openlibm with djgpp (and other
targets with missing C99 <math.h> functions). The <math.h> from openlibm
provides all the functions, but not the float_t and double_t typedefs.
By separating the autoconf checks for the functionsand the typedefs, we
don't disable support for all the functions just because those typedefs
are not present.
libstdc++-v3/ChangeLog:
PR libstdc++/109818
* acinclude.m4 (GLIBCXX_ENABLE_C99): Add separate check for
float_t and double_t and define HAVE_C99_FLT_EVAL_TYPES.
* config.h.in: Regenerate.
* configure: Regenerate.
* include/c_global/cmath (float_t, double_t): Guard using new
_GLIBCXX_HAVE_C99_FLT_EVAL_TYPES macro.
Similar to the three commits r14-908, r14-909 and r14-910, the
_GLIBCXX_USE_C99_MATH_TR1 macro is misleading when it is also used for
<cmath>, not only for <tr1/cmath> headers. It is also wrong, because the
configure checks for TR1 use -std=c++98 and a target might define the
C99 features for C++11 but not for C++98.
Add separate configure checks for the <math.h> functions using
-std=c++11 for the checks. Use the new macro defined by those checks in
the C++11-specific parts of <cmath>, and in <complex>, <random> etc.
The check that defines _GLIBCXX_NO_C99_ROUNDING_FUNCS is only needed for
the C++11 <cmath> checks, so remove that from GLIBCXX_CHECK_C99_TR1 and
only do it for GLIBCXX_ENABLE_C99.
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_ENABLE_C99): Add checks for C99 math
functions and define _GLIBCXX_USE_C99_MATH_FUNCS. Move checks
for C99 rounding functions to here.
(GLIBCXX_CHECK_C99_TR1): Remove checks for C99 rounding
functions from here.
* config.h.in: Regenerate.
* configure: Regenerate.
* include/bits/random.h: Use _GLIBCXX_USE_C99_MATH_FUNCS instead
of _GLIBCXX_USE_C99_MATH_TR1.
* include/bits/random.tcc: Likewise.
* include/c_compatibility/math.h: Likewise.
* include/c_global/cmath: Likewise.
* include/ext/random: Likewise.
* include/ext/random.tcc: Likewise.
* include/std/complex: Likewise.
* testsuite/20_util/from_chars/4.cc: Likewise.
* testsuite/20_util/from_chars/8.cc: Likewise.
* testsuite/26_numerics/complex/proj.cc: Likewise.
* testsuite/26_numerics/headers/cmath/60401.cc: Likewise.
* testsuite/26_numerics/headers/cmath/types_std_c++0x.cc:
Likewise.
* testsuite/lib/libstdc++.exp (check_v3_target_cstdint):
Likewise.
* testsuite/util/testsuite_random.h: Likewise.
As can be seen on the following testcase, for
std::{atan2,fmod,pow,copysign,fdim,fmax,fmin,hypot,nextafter,remainder,remquo,fma}
if one operand type is std::float{16,32,64,128}_t or std::bfloat16_t and
another one some integral type or some other floating point type which
promotes to the other operand's type, we can end up with endless recursion.
This is because of a declaration ordering problem in <cmath>, where the
float, double and long double overloads of those functions come before
the templates which use __gnu_cxx::__promote_{2,3}, but the
std::float{16,32,64,128}_t and std::bfloat16_t overloads come later in the
file. If the result of those promotions is _Float{16,32,64,128} or
__gnu_cxx::__bfloat16_t, say std::pow(_Float64, int) calls
std::pow(_Float64, _Float64) and the latter calls itself.
The following patch fixes that by moving those templates later in the file,
so that the calls from those templates see also the other overloads.
I think other templates in the file like e.g. isgreater etc. shouldn't be
a problem, because those just use __builtin_isgreater etc. in their bodies.
2023-05-17 Jakub Jelinek <jakub@redhat.com>
PR libstdc++/109883
* include/c_global/cmath (atan2, fmod, pow): Move
__gnu_cxx::__promote_2 using templates after _Float{16,32,64,128} and
__gnu_cxx::__bfloat16_t overloads.
(copysign, fdim, fmax, fmin, hypot, nextafter, remainder, remquo):
Likewise.
(fma): Move __gnu_cxx::__promote_3 using template after
_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t overloads.
* testsuite/26_numerics/headers/cmath/constexpr_std_c++23.cc: New test.
As with the two commits before this, the _GLIBCXX_USE_C99_CTYPE_TR1 and
_GLIBCXX_USE_C99_FENV_TR1 macros are misleading when they are also used
for <cctype> and <cfenv>, not only for TR1 headers. It is also wrong,
because the configure checks for TR1 use -std=c++98 and a target might
define the C99 features for C++11 but not for C++98.
Add separate configure checks for the <ctype.h> and <fenv.h> features using -std=c++11
for the checks. Use the new macros defined by those checks in the
C++11-specific parts of <cctype>, <cfenv>, and <fenv.h>.
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_USE_C99): Check for isblank in C++11
mode and define _GLIBCXX_USE_C99_CTYPE. Check for <fenv.h>
functions in C++11 mode and define _GLIBCXX_USE_C99_FENV.
* config.h.in: Regenerate.
* configure: Regenerate.
* include/c_compatibility/fenv.h: Check _GLIBCXX_USE_C99_FENV
instead of _GLIBCXX_USE_C99_FENV_TR1.
* include/c_global/cfenv: Likewise.
* include/c_global/cctype: Check _GLIBCXX_USE_C99_CTYPE instead
of _GLIBCXX_USE_C99_CTYPE_TR1.
The _GLIBCXX_USE_C99_STDINT_TR1 macro (and the comments about it in
acinclude.m4 and config.h) are misleading when it is also used for
<stdint>, not only <tr1/stdint>. It is also wrong, because the
configure checks for TR1 use -std=c++98 and a target might define
uint32_t etc. for C++11 but not for C++98.
Add a separate configure check for the <stdint.h> types using -std=c++11
for the checks. Use the result of that separate check in <cstdint> and
most other places that still depend on the macro (many uses of that
macro have been removed already). The remaining uses of the STDINT_TR1
macro are really for TR1, or are in the src/c++11/compatibility-*.cc
files, where we don't want/need to change the condition they depend on
(if those symbols were only exported when <stdint.h> types were
available for -std=c++98, then that's the condition we should continue
to use for whether to export the compat symbols now).
Make similar changes for the related _GLIBCXX_USE_C99_INTTYPES_TR1 and
_GLIBCXX_USE_C99_INTTYPES_WCHAR_T_TR1 macros, adding new macros for
non-TR1 uses.
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_USE_C99): Check for <stdint.h> types in
C++11 mode and define _GLIBCXX_USE_C99_STDINT. Check for
<inttypes.h> features in C++11 mode and define
_GLIBCXX_USE_C99_INTTYPES and _GLIBCXX_USE_C99_INTTYPES_WCHAR_T.
* config.h.in: Regenerate.
* configure: Regenerate.
* doc/doxygen/user.cfg.in (PREDEFINED): Add new macros.
* include/bits/chrono.h: Check _GLIBCXX_USE_C99_STDINT instead
of _GLIBCXX_USE_C99_STDINT_TR1.
* include/c_compatibility/inttypes.h: Check
_GLIBCXX_USE_C99_INTTYPES and _GLIBCXX_USE_C99_INTTYPES_WCHAR_T
instead of _GLIBCXX_USE_C99_INTTYPES_TR1 and
_GLIBCXX_USE_C99_INTTYPES_WCHAR_T_TR1.
* include/c_compatibility/stdatomic.h: Check
_GLIBCXX_USE_C99_STDINT instead of _GLIBCXX_USE_C99_STDINT_TR1.
* include/c_compatibility/stdint.h: Likewise.
* include/c_global/cinttypes: Check _GLIBCXX_USE_C99_INTTYPES
and _GLIBCXX_USE_C99_INTTYPES_WCHAR_T instead of
_GLIBCXX_USE_C99_INTTYPES_TR1 and
_GLIBCXX_USE_C99_INTTYPES_WCHAR_T_TR1.
* include/c_global/cstdint: Check _GLIBCXX_USE_C99_STDINT
instead of _GLIBCXX_USE_C99_STDINT_TR1.
* include/std/atomic: Likewise.
* src/c++11/cow-stdexcept.cc: Likewise.
* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc:
Likewise.
* testsuite/lib/libstdc++.exp (check_v3_target_cstdint):
Likewise.
The following patch
1) enables the std::float128_t overloads for x86 with glibc 2.26+
2) makes std::nextafter(std::float16_t, std::float16_t) and
std::nextafter(std::bfloat16_t, std::bfloat16_t) constexpr
3) adds (small) testsuite coverage for that
2022-10-21 Jakub Jelinek <jakub@redhat.com>
* config/os/gnu-linux/os_defines.h (_GLIBCXX_HAVE_FLOAT128_MATH):
Uncomment.
* include/c_global/cmath (nextafter(_Float16, _Float16)): Make it constexpr.
If std::__is_constant_evaluated() call __builtin_nextafterf16.
(nextafter(__gnu_cxx::__bfloat16_t, __gnu_cxx::__bfloat16_t)): Similarly
but call __builtin_nextafterf16b.
* testsuite/26_numerics/headers/cmath/nextafter_c++23.cc (test): Add
static assertions to test constexpr nextafter.
The following patch implements nextafter for std::{,b}float16_t,
though right now only without constexpr support, and adds a testcase for it.
The testcase unfortunately relevealed I've screwed up testing of my last
patch. I've tested earlier version of the patch with
--target_board=unix/-std=c++23
but didn't test the final version with that RUNTESTFLAGS, so missed
an invalid call to std::sph_neumann (too many arguments) in the test.
And, I've made a typo in the guard for numeric_limits (the reason
for the guard is I wanted to avoid defining a large macro that nothing
will then use because the std::{,b}float*_t types are C++23 only) and
so numeric_limits wasn't specialized for the types at all but
testsuite/18_support/headers/limits/synopsis_cxx23.cc test didn't
detect that.
In the nextafter implementation I'm calling __builtin_nextafterf
to get various required side-effects for nextafter from 0/-0, or from max
to inf or from min to largest subnormal to avoid needing to set errno
inline, or use inline asm specific for each processor to force math
evaluation barriers. Dunno if
#ifdef __INT16_TYPE__
using __float16_int_type = __INT16_TYPE__;
#else
using __float16_int_type = short int;
#endif
isn't too ugly, perhaps we could just blindly use short int and hope
or even assert it has the same size as _Float16 or __gnu_cxx::__bfloat16_t?
Only aarch64, arm, csky, gcn, x86, nvptx and riscv support these types
and all of them have 16-bit short (I think the only target with some
other short size is avr with certain command line switches where both
short and int are 8-bit, but such mode isn't compatible with C and C++
requirements).
2022-10-19 Jakub Jelinek <jakub@redhat.com>
PR c++/106652
* include/std/limits: Fix a typo, 202202L -> 202002L.
(numeric_limits::<_Float16>::radix, numeric_limits::<_Float32>::radix,
numeric_limits::<_Float64>::radix, numeric_limits::<_Float128>::radix,
numeric_limits::<__gnu_cxx::__bfloat16_t>::radix): Use __FLT_RADIX__
macro instead of type specific macros.
* include/c_global/cmath (nextafter(_Float16, _Float16)): New
overload.
(nextafter(__gnu_cxx::__bfloat16_t, __gnu_cxx::__bfloat16_t)):
Likewise.
* testsuite/26_numerics/headers/cmath/functions_std_c++23.cc
(test_functions): Uncomment nextafter test. Fix up sph_neumann call.
* testsuite/26_numerics/headers/cmath/nextafter_c++23.cc: New test.
The following patch is partial support for std::float{16,32,64,128}_t
and std::bfloat16_t in libstdc++.
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p1467r9.html
says that <ostream>, <istream>, <charconv> and <complex>
need changes toom, but that isn't implemented so far.
In <cmath> the only thing missing I'm aware of is
std::nextafter std::float16_t and std::bfloat16_t overloads (I think
we probably need to implement that out of line somewhere, or inline? - might
need inline asm barriers) and std::nexttoward overloads (those are
intentional, you said there is a LWG issue about that).
Also, this patch has the glibc 2.26+ std::float128_t support for platforms
where long double isn't IEEE quad format temporarily disabled
because it depends on
https://gcc.gnu.org/pipermail/gcc-patches/2022-October/603665.html
changes which aren't in yet.
The patch also doesn't include any testcases to cover the <type_traits>
changes, it isn't clear to me where to put that.
2022-10-18 Jakub Jelinek <jakub@redhat.com>
PR c++/106652
* include/std/stdfloat: New file.
* include/std/numbers (__glibcxx_numbers): Define and use it
for __float128 explicit instantiations as well as
_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t.
* include/std/atomic (atomic<_Float16>, atomic<_Float32>,
atomic<_Float64>, atomic<_Float128>, atomic<__gnu_cxx::__bfloat16_t>):
New explicit instantiations.
* include/std/type_traits (__is_floating_point_helper<_Float16>,
__is_floating_point_helper<_Float32>,
__is_floating_point_helper<_Float64>,
__is_floating_point_helper<_Float128>,
__is_floating_point_helper<__gnu_cxx::__bfloat16_t>): Likewise.
* include/std/limits (__glibcxx_concat3_, __glibcxx_concat3,
__glibcxx_float_n): Define.
(numeric_limits<_Float16>, numeric_limits<_Float32>,
numeric_limits<_Float64>, numeric_limits<_Float128>,
numeric_limits<__gnu_cxx::__bfloat16_t>): New explicit instantiations.
* include/bits/std_abs.h (abs): New overloads for
_Float{16,32,64,128} and __gnu_cxx::__bfloat16_t.
* include/bits/c++config (_GLIBCXX_LDOUBLE_IS_IEEE_BINARY128): Define
if long double is IEEE quad.
(__gnu_cxx::__bfloat16_t): New using.
* include/c_global/cmath (acos, asin, atan, atan2, ceil, cos, cosh,
exp, fabs, floor, fmod, frexp, ldexp, log, log10, modf, pow, sin,
sinh, sqrt, tan, tanh, fpclassify, isfinite, isinf, isnan, isnormal,
signbit, isgreater, isgreaterequal, isless, islessequal,
islessgreater, isunordered, acosh, asinh, atanh, cbrt, copysign, erf,
erfc, exp2, expm1, fdim, fma, fmax, fmin, hypot, ilogb, lgamma,
llrint, llround, log1p, log2, logb, lrint, lround, nearbyint,
nextafter, remainder, rint, round, scalbln, scalbn, tgamma, trunc,
lerp): New overloads with _Float{16,32,64,128} or
__gnu_cxx::__bfloat16_t types.
* config/os/gnu-linux/os_defines.h (_GLIBCXX_HAVE_FLOAT128_MATH):
Prepare for definition if glibc 2.26 and later implements *f128 APIs
but comment out the actual definition for now.
* include/ext/type_traits.h (__promote<_Float16>, __promote<_Float32>,
__promote<_Float64>, __promote<_Float128>,
__promote<__gnu_cxx::__bfloat16_t>): New specializations.
* include/Makefile.am (std_headers): Add stdfloat.
* include/Makefile.in: Regenerated.
* include/precompiled/stdc++.h: Include stdfloat.
* testsuite/18_support/headers/stdfloat/types_std.cc: New test.
* testsuite/18_support/headers/limits/synopsis_cxx23.cc: New test.
* testsuite/26_numerics/headers/cmath/c99_classification_macros_c++23.cc:
New test.
* testsuite/26_numerics/headers/cmath/functions_std_c++23.cc: New test.
* testsuite/26_numerics/numbers/4.cc: New test.
* testsuite/29_atomics/atomic_float/requirements_cxx23.cc: New test.
When gcc/config.gcc defines use_gcc_stdin=wrap, GCC's <stdint.h> tries
to use libc's <stdint.h> unless -ffreestanding is used.
When libstdc++ is configured --disable-hosted-libstdcxx we want
<cstdint> to work even without -ffreestanding being given. This is a
kluge to make it include GCC's <stdint-gcc.h> directly even without
-ffreestanding.
libstdc++-v3/ChangeLog:
PR libstdc++/107134
* include/c_global/cstdint [!_GLIBCXX_HOSTED]: Include
<stdint-gcc.h> directly.
This adds checks for _GLIBCXX_HOSTED to a number of headers which are
not currently installed for freestanding, but need to be for P1642R11
support. For example, <iterator> needs to be installed for C++23
freestanding mode, but without stream iterators and streambuf iterators.
Similarly, <memory> needs to be installed, but without std::allocator
and std::shared_ptr. This change disables the non-freestanding parts of
those headers.
libstdc++-v3/ChangeLog:
PR libstdc++/106953
* include/backward/auto_ptr.h [!_GLIBCXX_HOSTED]: Do not define
shared_ptr members.
* include/bits/alloc_traits.h [!_GLIBCXX_HOSTED]: Do not declare
std::allocator_traits<std::allocator<T>> specializations for
freestanding.
* include/bits/memoryfwd.h [!_GLIBCXX_HOSTED] (allocator): Do
not declare for freestanding.
* include/bits/stl_algo.h [!_GLIBCXX_HOSTED] (stable_partition):
Do not define for freestanding.
[!_GLIBCXX_HOSTED] (merge, stable_sort): Do not use temporary
buffers for freestanding.
* include/bits/stl_algobase.h [!_GLIBCXX_HOSTED]: Do not declare
streambuf iterators and overloaded algorithms using them.
* include/bits/stl_uninitialized.h [!_GLIBCXX_HOSTED]: Do not
define specialized overloads for std::allocator.
* include/bits/unique_ptr.h [!_GLIBCXX_HOSTED] (make_unique)
(make_unique_for_overwrite, operator<<): Do not define for
freestanding.
* include/c_global/cstdlib [!_GLIBCXX_HOSTED] (_Exit): Declare.
Use _GLIBCXX_NOTHROW instead of throw().
* include/debug/assertions.h [!_GLIBCXX_HOSTED]: Ignore
_GLIBCXX_DEBUG for freestanding.
* include/debug/debug.h [!_GLIBCXX_DEBUG]: Likewise.
* include/std/bit [!_GLIBCXX_HOSTED]: Do not use the custom
__int_traits if <ext/numeric_traits.h> is available.
* include/std/functional [!_GLIBCXX_HOSTED]: Do not include
headers that aren't valid for freestanding.
(boyer_moore_searcher, boyer_moore_horspool_searcher): Do not
define for freestanding.
* include/std/iterator [!_GLIBCXX_HOSTED]: Do not include
headers that aren't valid for freestanding.
* include/std/memory [!_GLIBCXX_HOSTED]: Likewise.
* include/std/ranges [!_GLIBCXX_HOSTED] (istream_view): Do not
define for freestanding.
(views::__detail::__is_basic_string_view) [!_GLIBCXX_HOSTED]:
Do not define partial specialization for freestanding.
This patch completes implementation of the C++20 proposal P0482R6 [1] by
adding declarations of std::c8rtomb() and std::mbrtoc8() in <cuchar> if
provided by the C library in <uchar.h>.
This patch addresses feedback provided in response to a previous patch
submission [2].
Autoconf changes determine if the C library declares c8rtomb and mbrtoc8
at global scope when uchar.h is included and compiled with either
-fchar8_t or -std=c++20. New _GLIBCXX_USE_UCHAR_C8RTOMB_MBRTOC8_FCHAR8_T
and _GLIBCXX_USE_UCHAR_C8RTOMB_MBRTOC8_CXX20 configuration macros
reflect the probe results. The <cuchar> header declares these functions
in the std namespace only if available and the _GLIBCXX_USE_CHAR8_T
configuration macro is defined (by default it is defined if the C++20
__cpp_char8_t feature test macro is defined)
Patches to glibc to implement c8rtomb and mbrtoc8 have been submitted [3].
New tests validate the presence of these declarations. The tests pass
trivially if the C library does not provide these functions. Otherwise
they ensure that the functions are declared when <cuchar> is included
and either -fchar8_t or -std=c++20 is enabled.
1]: WG21 P0482R6
"char8_t: A type for UTF-8 characters and strings (Revision 6)"
https://wg21.link/p0482r6
[2]: [PATCH] C++ P0482R6 char8_t: declare std::c8rtomb and std::mbrtoc8
if provided by the C library
https://gcc.gnu.org/pipermail/libstdc++/2021-June/052685.html
[3]: "C++20 P0482R6 and C2X N2653"
[Patch 0/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135061.html
[Patch 1/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135062.html
[Patch 2/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135063.html
[Patch 3/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135064.html
libstdc++-v3/ChangeLog:
* acinclude.m4: Define config macros if uchar.h provides
c8rtomb() and mbrtoc8().
* config.h.in: Regenerate.
* configure: Regenerate.
* include/c_compatibility/uchar.h (c8rtomb, mbrtoc8): Define.
* include/c_global/cuchar (c8rtomb, mbrtoc8): Likewise.
* include/c_std/cuchar (c8rtomb, mbrtoc8): Likewise.
* testsuite/21_strings/headers/cuchar/functions_std_cxx20.cc:
New test.
* testsuite/21_strings/headers/cuchar/functions_std_fchar8_t.cc:
New test.
None of these traits depend on libc support for wchar_t, so they should
be defined unconditionally. The wchar_t type is always defined in C++.
libstdc++-v3/ChangeLog:
PR libstdc++/98725
* include/c_global/cstddef [!_GLIBCXX_USE_WCHAR_T]
(__byte_operand<wchar_t>): Define specialization.
* include/std/type_traits (__make_signed<wchar_t>)
(__make_unsigned<wchar_t>): Remove redundant check for
__WCHAR_TYPE__ being defined.
* include/tr1/type_traits [!_GLIBCXX_USE_WCHAR_T]
(__is_integral_helper<wchar_t>): Likewise.
The [cmath.syn] p1 wording about additional overloads sufficient to
handle any arithmetic types also applies to std::lerp. This adds a new
overload of std::lerp that does the required promotions to support
arguments of arbitrary arithmetic types.
A new __promoted_t alias template is added, which the C++17 function
templates std::hypot and std::lerp can use to avoid instantiating the
__promote_3 class template.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/101870
* include/c_global/cmath (hypot): Use __promoted_t.
(lerp): Add new overload accepting any arithmetic types.
* include/ext/type_traits.h (__promoted_t): New alias template.
* testsuite/26_numerics/lerp.cc: Moved to...
* testsuite/26_numerics/lerp/1.cc: ...here.
* testsuite/26_numerics/lerp/constexpr.cc: New test.
* testsuite/26_numerics/lerp/version.cc: New test.
Add [[nodiscard]] to functions that are effectively just a static_cast,
as per P2351. Also add it to std::addressof.
libstdc++-v3/ChangeLog:
* include/bits/move.h (forward, move, move_if_noexcept)
(addressof): Add _GLIBCXX_NODISCARD.
* include/bits/ranges_cmp.h (identity::operator()): Add
nodiscard attribute.
* include/c_global/cstddef (to_integer): Likewise.
* include/std/bit (bit_cast): Likewise.
* include/std/utility (as_const, to_underlying): Likewise.
The implementation of midpoint used for integral types is due to Howard
Hinnant and avoids a branch for int and larger types (but not for chars
and shorts).
The midpoint and lerp functions for floating point types come straight
from the P0811R3 proposal, with no attempt at optimization.
* include/c_compatibility/math.h [C++20] (lerp): Add using
declaration.
* include/c_global/cmath [C++20] (__cpp_lib_interpolate): Define.
(__lerp): Define function template to implement lerp.
(lerp(float, float, float), lerp(double, double, double))
(lerp(long double, long double, long double)): Define for C++20.
* include/std/numeric [C++20] (__cpp_lib_interpolate): Define.
(midpoint(T, T), midpoint(T*, T*)): Define.
* include/std::version [C++20] (__cpp_lib_interpolate): Define.
* testsuite/26_numerics/lerp.cc: New test.
* testsuite/26_numerics/midpoint/floating.cc: New test.
* testsuite/26_numerics/midpoint/integral.cc: New test.
* testsuite/26_numerics/midpoint/pointer.cc: New test.
From-SVN: r269398
PR libstdc++/79017
* acinclude.m4 (GLIBCXX_CHECK_C99_TR1): Check for llrint and llround
functions separately on darwin and if they're missing define
_GLIBCXX_NO_C99_ROUNDING_FUNCS.
* config.h.in: Regenerate.
* configure: Regenerate.
* include/c_global/cmath [_GLIBCXX_NO_C99_ROUNDING_FUNCS] (llrint)
(llrintf, llrintl, llround, llroundf, llroundl): Do not define.
From-SVN: r244231
