The use of npos triggers a diagnostic as described in PR c++/101361.
This change replaces the use of npos with the exact length, which is
already known. We can further simplify it by inlining the effects of
compare and substr, avoiding the redundant range checks in the latter.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR c++/101361
* include/std/string_view (ends_with): Use traits_type::compare
directly.
When I added the new C++23 constructor I added a conditional include of
<bits/ranges_base.h>, which was already being included unconditionally.
This removes the unconditional include but changes the condition for the
other one, so it's used for C++20 as well.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/string_view: Only include <bits/ranges_base.h>
once, and only for C++20 and later.
The std::as_writable_bytes function should be constrained to only accept
writable spans. Currently it can be called but then gives an error in
the function body.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/101411
* include/std/span (as_writable_bytes): Add requires-clause.
* testsuite/23_containers/span/101411.cc: New test.
This reverts the changes in r12-1778 which added a noexcept-specifier to
std::unique_ptr<T[]>::operator[], and the changes in r12-1844 which
tried to make it work with incomplete types (for PR 101236).
The noexcept-specifier is not required by the standard, and is causing
regressions, so just remove it.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/101271
* include/bits/unique_ptr.h (unique_ptr<T[],D>::operator[]):
Remove noexcept-specifier.
(unique_ptr<T[],D>::_S_nothrow_deref): Remove.
* testsuite/20_util/unique_ptr/lwg2762.cc: Remove checks for
operator[].
This attempst to improve the doxygen output to work around what seems to
be some bugs in doxygen (issues 8635 and 8638).
The @addtogroup command doesn't work for entities inside a nested
namespace (see 8635) so we need to close and reopen groups on entering
and elaving nested namespaces. This fixes the problem that
chrono::duration and chrono::time_point were not documented in the
"Time" documentation group. I am unable to make the path classes appear
as part of their relevant groups (File System and Filesystem TS), nor
the contents of <exception> or <system_error>. I have made some minor
improvements to the docs for those types, including starting to address
PR 97001 by adding @since to the doxygen comments.
This change also excludes the <experimental/bits/net.h> header from
Doxygen processing, so we don't get an unwanted "Networking-ts" group
in the documentation.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* doc/doxygen/doxygroups.cc: Fix docs for std::literals.
* doc/doxygen/user.cfg.in: Exclude the Networking TS header.
Add some more predefined macros.
* include/bits/fs_fwd.h: Move @addtogroup commands inside
namespaces. Add better documentation.
* include/bits/fs_path.h: Likewise.
* include/experimental/bits/fs_fwd.h: Likewise.
* include/experimental/bits/fs_path.h: Likewise.
* include/ext/throw_allocator.h: Fix typo and improve docs.
* include/std/chrono: Move @addtogroup commands.
* include/std/system_error: Move @addtogroup commands.
* libsupc++/exception: Improve documentation.
* libsupc++/exception.h: Add @since documentation.
This defines some new Doxygen groups for C++17 variable templates and
for the contents of <experimental/type_traits>. By documenting the group
as a whole and adding each template to a group we don't need to document
them individually.
Also mark more internals with "@cond undocumented" so that Doxygen
ignores them by default. Also make Doxygen process <experimental/simd>.
For some reason, many of the class templates in <type_traits> do not
appear in the "Metaprogramming" group. For example, add_cv,
remove_extent, and all the is_xxx_constructible and is_xxx_assignable
traits. For some reason, Doxygen doesn't include them in the group,
despite doing it correctly for other traits in the same header.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/101258
* doc/doxygen/user.cfg.in (INPUT): Add <experimental/simd>.
(COLS_IN_ALPHA_INDEX): Remove obsolete tag.
(PREDEFINED): Add/fix some more macros that need to be expanded.
* include/bits/random.h: Stop Doxygen from documenting internal
implementation details.
* include/bits/random.tcc: Likewise.
* include/bits/this_thread_sleep.h: Fix @file name.
* include/experimental/bits/simd.h: Add to Doxygen group. Do not
document internal implementation details.
* include/experimental/bits/simd_detail.h: Do not document
internal implementation details.
* include/experimental/simd: Define Doxygen groups.
* include/experimental/type_traits: Improve documentation for
the header file. Define groups. Use @since commands.
* include/std/scoped_allocator (scoped_allocator_adaptor): Move
declaration before undocumented region.
* include/std/type_traits (true_type, false_type): Use using
declaration instead of typedef.
(is_invocable_v, is_nothrow_invocable_v, is_invocable_r_v)
(is_nothrow_invocable_r_v): Move definitions next to other C++17
variable templates.
Do not document internal implementation details. Move misplaced
group-end command. Define group for variable templates.
* include/std/variant: Do not document internal implementation
details.
* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error
line number.
Since C++17 the static members of the random number engines are
implicitly inline, so don't need definitions.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/random.tcc [__cpp_inline_variables]: Remove
redundant definitions of static constexpr member variables.
* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error
line number.
These function templates are explicitly specialized for char and wchar_t
streambufs, so the explicit instantiations do nothing. Remove them, to
avoid confusion.
libstdc++-v3/ChangeLog:
* include/bits/streambuf.tcc (__copy_streambufs_eof): Remove
explicit instantiation declarations.
* src/c++11/streambuf-inst.cc (__copy_streambufs_eof): Remove
explicit instantiation definitions.
PR libstdc++/101236 shows that LLVM depends on being able to use
unique_ptr<T[]>::operator[] when T is incomplete. This is undefined, but
previously worked with libstdc++. When I added the conditional noexcept
to that operator we started to diagnose the incomplete type.
This change restores support for that case, by making the noexcept
condition check that the type is complete before checking whether
indexing on the pointer can throw. A workaround for PR c++/101239 is
needed to avoid a bogus error where G++ fails to do SFINAE on the
ill-formed p[n] expression and gets an ICE. Instead of checking that the
p[n] expression is valid in the trailing-return-type, we only check that
the element_type is complete.
libstdc++-v3/ChangeLog:
PR libstdc++/101236
* include/bits/unique_ptr.h (unique_ptr<T[], D>::operator[]):
Fail gracefully if element_type is incomplete.
* testsuite/20_util/unique_ptr/cons/incomplete.cc: Clarify that
the standard doesn't require this test to work for array types.
* testsuite/20_util/unique_ptr/lwg2762.cc: Check that incomplete
types can be used with array specialization.
* testsuite/20_util/unique_ptr/101236.cc: New test.
For C++11 std::ws changed to be an unformatted input function, meaning
it constructs a sentry and sets badbit on exceptions.
libstdc++-v3/ChangeLog:
* doc/xml/manual/intro.xml: Document LWG 415 change.
* doc/html/manual/bugs.html: Regenerate.
* include/bits/istream.tcc (ws): Create sentry and catch
exceptions.
* testsuite/27_io/basic_istream/ws/char/lwg415.cc: New test.
* testsuite/27_io/basic_istream/ws/wchar_t/lwg415.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.
N3168 added the requirement that the [ostream.seeks] functions create a
sentry object. Nothing in the requirements of those functions says
anything about catching exceptions and setting badbit.
As well as not catching exceptions, this change results in another
observable behaviour change. Previously seeking on a stream with eofbit
set would work (as long as badbit and failbit weren't set). The
construction of a sentry causes failbit to be set when eofbit is set,
which causes the seek to fail. It is necessary to clear the eofbit
before seeking now.
libstdc++-v3/ChangeLog:
* include/bits/ostream.tcc (sentry): Only set failbit if badbit
is set, not if eofbit is set.
(tellp, seekp, seekp): Create sentry object. Do not set badbit
on exceptions.
* testsuite/27_io/basic_ostream/seekp/char/exceptions_badbit_throw.cc:
Adjust expected behaviour.
* testsuite/27_io/basic_ostream/seekp/wchar_t/exceptions_badbit_throw.cc:
Likewise.
* testsuite/27_io/basic_ostream/tellp/char/exceptions_badbit_throw.cc:
Likewise.
* testsuite/27_io/basic_ostream/tellp/wchar_t/exceptions_badbit_throw.cc:
Likewise.
* testsuite/27_io/basic_ostream/seekp/char/n3168.cc: New test.
* testsuite/27_io/basic_ostream/seekp/wchar_t/n3168.cc: New test.
* testsuite/27_io/basic_ostream/tellp/char/n3168.cc: New test.
* testsuite/27_io/basic_ostream/tellp/wchar_t/n3168.cc: New test.
The proposed resolution for the inconsistent noexcept-specifiers in the
spec is to remove it from bto hthe assignment operator and swap.
libstdc++-v3/ChangeLog:
* include/std/syncstream (basic_syncbuf::swap()): Remove
noexcept, as per LWG 3498.
The __bit_cast function was a hack to achieve what __builtin_bit_cast
can do, therefore use __builtin_bit_cast if possible. However,
__builtin_bit_cast cannot be used to cast from/to fixed_size_simd, since
it isn't trivially copyable (in the language sense — in principle it
is). Therefore add __proposed::simd_bit_cast to enable the use case
required in the test framework.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd.h (__bit_cast): Implement via
__builtin_bit_cast #if available.
(__proposed::simd_bit_cast): Add overloads for simd and
simd_mask, which use __builtin_bit_cast (or __bit_cast #if not
available), which return an object of the requested type with
the same bits as the argument.
* include/experimental/bits/simd_math.h: Use simd_bit_cast
instead of __bit_cast to allow casts to fixed_size_simd.
(copysign): Remove branch that was only required if __bit_cast
cannot be constexpr.
* testsuite/experimental/simd/tests/bits/test_values.h: Switch
from __bit_cast to __proposed::simd_bit_cast since the former
will not cast fixed_size objects anymore.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd_x86.h (_S_trunc, _S_floor)
(_S_ceil): Set bit 8 (_MM_FROUND_NO_EXC) on AVX and SSE4.1
roundp[sd] calls.
This improves codegen of ldexp if AVX512VL is available.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd_x86.h (_S_ldexp): The AVX512F
implementation doesn't require a _VecBltnBtmsk ABI tag, it
requires either a 64-Byte input (in which case AVX512F must be
available) or AVX512VL.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd_math.h: Undefine internal
macros after use.
(frexp): Move #if to a more sensible position and reformat
preceding code.
(logb): Call _SimdImpl::_S_logb for fixed_size instead of
duplicating the code here.
(modf): Simplify condition.
fabs(int) returns double, this one didn't. This overload is not
specified in the Parallelism TS 2. Also remove the comment about labs
and llabs: it doesn't belong here.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd_math.h (fabs): Remove
fabs(simd<integral>) overload.
Sometimes fixed_size objects will get unnecessarily copied on the stack.
The simd implementation should never pass _SimdTuple by value to avoid
requiring the optimizer to see through these copies.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd_converter.h
(_SimdConverter::operator()): Pass _SimdTuple by const-ref.
* include/experimental/bits/simd_fixed_size.h
(_GLIBCXX_SIMD_FIXED_OP): Pass binary operator _SimdTuple
arguments by const-ref.
(_S_masked_unary): Pass _SimdTuple by const-ref.
This helper type became unused at some point.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd_fixed_size.h
(_AbisInSimdTuple): Removed.
This also resolves a test failure on aarch64 with -ffast-math and
fixed_size<N> with large N.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd.h: Add missing operator~
overload for simd<floating-point> to __float_bitwise_operators.
* include/experimental/bits/simd_builtin.h
(_SimdImplBuiltin::_S_complement): Bitcast to int (and back) to
implement complement for floating-point vectors.
* include/experimental/bits/simd_fixed_size.h
(_SimdImplFixedSize::_S_copysign): New function, forwarding to
copysign implementation of _SimdTuple members.
* include/experimental/bits/simd_math.h (copysign): Call
_SimdImpl::_S_copysign for fixed_size arguments. Simplify
generic copysign implementation using the new ~ operator.
The LWG issue proposes to add a conditional noexcept-specifier to
std::unique_ptr's dereference operator. The issue is currently in
Tentatively Ready status, but even if it isn't voted into the draft, we
can do it as a conforming extensions. This commit also adds a similar
noexcept-specifier to operator[] for the unique_ptr<T[], D> partial
specialization.
Also ensure that all dereference operators for shared_ptr are noexcept,
and adds tests for the std::optional accessors modified by the issue,
which were already noexcept in our implementation.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/shared_ptr_base.h (__shared_ptr_access::operator[]):
Add noexcept.
* include/bits/unique_ptr.h (unique_ptr::operator*): Add
conditional noexcept as per LWG 2762.
* testsuite/20_util/shared_ptr/observers/array.cc: Check that
dereferencing cannot throw.
* testsuite/20_util/shared_ptr/observers/get.cc: Likewise.
* testsuite/20_util/optional/observers/lwg2762.cc: New test.
* testsuite/20_util/unique_ptr/lwg2762.cc: New test.
Simple change to std::chrono::year::is_leap. If a year is multiple of 100,
then it's divisible by 400 if and only if it's divisible by 16. The latter
allows for better code generation.
The expression is then either y%16 or y%4 which are both powers of two
and so it can be rearranged to use simple bitmask operations.
Co-authored-by: Jonathan Wakely <jwakely@redhat.com>
Co-authored-by: Ulrich Drepper <drepper@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/chrono (chrono::year::is_leap()): Optimize.
The std::try_lock and std::lock algorithms can use iteration instead of
recursion when all lockables have the same type and can be held by an
array of unique_lock<L> objects.
By making this change to __detail::__try_lock_impl it also benefits
__detail::__lock_impl, which uses it. For std::lock we can just put the
iterative version directly in std::lock, to avoid making any call to
__detail::__lock_impl.
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
Co-authored-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/std/mutex (lock): Replace recursion with iteration
when lockables all have the same type.
(__detail::__try_lock_impl): Likewise. Pass lockables as
parameters, instead of a tuple. Always lock the first one, and
recurse for the rest.
(__detail::__lock_impl): Adjust call to __try_lock_impl.
(__detail::__try_to_lock): Remove.
* testsuite/30_threads/lock/3.cc: Check that mutexes are locked.
* testsuite/30_threads/lock/4.cc: Also test non-heterogeneous
arguments.
* testsuite/30_threads/unique_lock/cons/60497.cc: Also check
std::try_lock.
* testsuite/30_threads/try_lock/5.cc: New test.
This removes the non-functional garbage colection support from <memory>,
as proposed for C++23 by P2186R2.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/memory (declare_reachable, undeclare_reachable)
(declare_no_pointers, undeclare_no_pointers, get_pointer_safety)
(pointer_safety): Only define for C++11 to C++20 inclusive.
* testsuite/20_util/pointer_safety/1.cc: Do not run for C++23.
This ensures that the std::seed_seq initializer-list constructor will
not be used for list-initialization unless the initializers in the list
are integers. This allows list-initialization syntax to be used with a
pair of pointers and for that to use the appropriate constructor.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/random.h (seed_seq): Constrain initializer-list
constructor.
* include/bits/random.tcc (seed_seq): Add template parameter.
* testsuite/26_numerics/random/seed_seq/cons/default.cc: Check
for noexcept.
* testsuite/26_numerics/random/seed_seq/cons/initlist.cc: Check
constraints.
libstdc++-v3/ChangeLog:
PR libstdc++/100806
* include/bits/semaphore_base.h (__atomic_semaphore::_M_release):
Force _M_release() to wake all waiting threads.
* testsuite/30_threads/semaphore/100806.cc: New test.
The current std::lock algorithm is the one called "persistent" in Howard
Hinnant's https://howardhinnant.github.io/dining_philosophers.html post.
While it tends to perform acceptably fast, it wastes a lot of CPU cycles
by continuously locking and unlocking the uncontended mutexes.
Effectively, it's a spin lock with no back-off.
This replaces it with the one Howard calls "smart and polite". It's
smart, because when a Mi.try_lock() call fails because mutex Mi is
contended, the algorithm reorders the mutexes until Mi is first, then
calls Mi.lock(), to block until Mi is no longer contended. It's
polite because it uses std::this_thread::yield() between the failed
Mi.try_lock() call and the Mi.lock() call. (In reality it uses
__gthread_yield() directly, because using this_thread::yield() would
require shuffling code around to avoid a circular dependency.)
This version of the algorithm is inspired by some hints from Howard, so
that it has strictly bounded stack usage. As the comment in the code
says:
// This function can recurse up to N levels deep, for N = 1+sizeof...(L1).
// On each recursion the lockables are rotated left one position,
// e.g. depth 0: l0, l1, l2; depth 1: l1, l2, l0; depth 2: l2, l0, l1.
// When a call to l_i.try_lock() fails it recurses/returns to depth=i
// so that l_i is the first argument, and then blocks until l_i is locked.
The 'i' parameter is the desired permuation of the lockables, and the
'depth' parameter is the depth in the call stack of the current
instantiation of the function template. If i == depth then the function
calls l0.lock() and then l1.try_lock()... for each lockable in the
parameter pack l1. If i > depth then the function rotates the lockables
to the left one place, and calls itself again to go one level deeper.
Finally, if i < depth then the function returns to a shallower depth,
equivalent to a right rotate of the lockables. When a call to
try_lock() fails, i is set to the index of the contended lockable, so
that the next call to l0.lock() will use the contended lockable as l0.
This commit also replaces the std::try_lock implementation details. The
new code is identical in behaviour, but uses a pair of constrained
function templates. This avoids instantiating a class template, and is a
litle simpler to call where used in std::__detail::__lock_impl and
std::try_lock.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/mutex (__try_to_lock): Move to __detail namespace.
(struct __try_lock_impl): Replace with ...
(__detail::__try_lock_impl<Idx>(tuple<Lockables...>&)): New
function templates to implement std::try_lock.
(try_lock): Use new __try_lock_impl.
(__detail::__lock_impl(int, int&, L0&, L1&...)): New function
template to implement std::lock.
(lock): Use __lock_impl.
r12-1606 bumped the value of __cpp_lib_ranges defined in <version>,
but this macro is also defined in <bits/range_cmp.h>, so it needs to
be updated there as well.
libstdc++-v3/ChangeLog:
* include/bits/ranges_cmp.h (__cpp_lib_ranges): Adjust value.
This implements the new views::split from P2210R2 "Superior String
Splitting".
libstdc++-v3/ChangeLog:
* include/std/ranges (__non_propagating_cache::operator bool):
Define for split_view::begin().
(split_view): Define as per P2210.
(views::__detail::__can_split_view): Define.
(views::_Split, views::split): Define.
* testsuite/std/ranges/adaptors/100577.cc (test01, test02):
Test views::split.
* testsuite/std/ranges/adaptors/split.cc: New test.
* testsuite/std/ranges/p2325.cc (test08a): New test.
* testsuite/std/ranges/p2367.cc (test01): Test views::split.
This mostly mechanical patch renames split to lazy_split throughout.
libstdc++-v3/ChangeLog:
* include/std/ranges: Rename views::split to views::lazy_split,
split_view to lazy_split_view, etc. throughout.
* testsuite/std/ranges/*: Likewise.
This implements the part of P2210R2 "Superior String Splitting" that
resolves LWG 3478.
libstdc++-v3/ChangeLog:
* include/std/ranges (split_view::_OuterIter::__at_end):
Check _M_trailing_empty.
(split_view::_OuterIter::_M_trailing_empty): Define this
data member.
(split_view::_OuterIter::operator++): Set _M_trailing_empty
appropriately.
(split_view::_OuterIter::operator==): Compare
_M_trailing_empty.
* testsuite/std/ranges/adaptors/100479.cc (test03): Expect two
split parts instead of one.
* testsuite/std/ranges/adaptors/split.cc (test11): New test.
libstdc++-v3/ChangeLog:
* include/std/ranges (transform_view::_Iterator::_S_iter_concept):
Consider _Base instead of _Vp as per LWG 3555.
(elements_view::_Iterator::_S_iter_concept): Likewise.
libstdc++-v3/ChangeLog:
* include/std/ranges (split_view::_OuterIter::value_type::begin):
Remove the non-const overload, and remove the copyable constraint
on the const overload as per LWG 3553.
libstdc++-v3/ChangeLog:
* include/bits/stl_iterator.h
(__detail::__common_iter_use_postfix_proxy): Add
move_constructible constraint as per LWG 3546.
(common_iterator::__postfix_proxy): Adjust initializer of
_M_keep as per LWG 3546.
This rewrites ranges::minmax and ranges::minmax_element so that it
performs at most 3*N/2 many comparisons, as required by the standard.
In passing, this also fixes PR100387 by avoiding a premature std::move
in ranges::minmax and in std::shift_right.
PR libstdc++/100387
libstdc++-v3/ChangeLog:
* include/bits/ranges_algo.h (__minmax_fn::operator()): Rewrite
to limit comparison complexity to 3*N/2.
(__minmax_element_fn::operator()): Likewise.
(shift_right): Avoid premature std::move of __result.
* testsuite/25_algorithms/minmax/constrained.cc (test04, test05):
New tests.
* testsuite/25_algorithms/minmax_element/constrained.cc (test02):
Likewise.
The standard does not require the iterator's value type to be
convertible to the result type, it only requires that the result of
dereferencing the iterator can be passed to the binary function.
libstdc++-v3/ChangeLog:
PR libstdc++/95833
* include/std/numeric (reduce(Iter, Iter, T, BinaryOp)): Replace
incorrect static_assert with ones matching the 'Mandates'
conditions in the standard.
* testsuite/26_numerics/reduce/95833.cc: New test.
The <ranges> header defines simplified copies of some ranges algorithms
in order to avoid including the entirety of ranges_algo.h. A subsequent
patch is going to want to use ranges::search in <ranges> as well, and
that algorithm is more complicated compared to the other copied ones.
So rather than additionally copying ranges::search into <ranges>, this
patch splits out all the ranges algos used by <ranges> (including
ranges::search) from ranges_algo.h to ranges_util.h, and deletes the
simplified copies in <ranges>. This seems like the best place to
put these algorithms, as ranges_util.h is currently included only from
<ranges> and ranges_algo.h.
libstdc++-v3/ChangeLog:
* include/bits/ranges_algo.h (__find_fn, find, __find_if_fn)
(find_if, __find_if_not_fn, find_if_not, _in_in_result)
(__mismatch_fn, mismatch, __search_fn, search): Move to ...
* include/bits/ranges_util.h: ... here.
* include/std/ranges (__detail::find, __detail::find_if)
(__detail::find_if_not, __detail::mismatch): Remove.
(filter_view): Use ranges::find_if instead.
(drop_while_view): Use ranges::find_if_not instead.
(split_view): Use ranges::find and ranges::mismatch instead.
This implements the wording changes of P2325R3 "Views should not be
required to be default constructible". Changes are relatively
straightforward, besides perhaps those to __box (which now stands
for copyable-box instead of semiregular-box) and __non_propagating_cache.
For __box, this patch implements the recommended practice to also avoid
std::optional when the boxed type is nothrow_move/copy_constructible.
For __non_propagating_cache, now that it's used by split_view::_M_current,
we need to add assignment from a value of the underlying type to the
subset of the std::optional API implemented for the cache (needed by
split_view::begin()). Hence the new __non_propagating_cache::operator=
overload.
In passing, this fixes the undesirable list-init in the constructors of
the partial specialization of __box as reported in PR100475 comment #7.
libstdc++-v3/ChangeLog:
* include/bits/iterator_concepts.h (weakly_incrementable): Remove
default_initializable requirement.
* include/bits/ranges_base.h (ranges::view): Likewise.
* include/bits/ranges_util.h (subrange): Constrain the default
ctor.
* include/bits/stl_iterator.h (back_insert_iterator): Remove the
default ctor.
(front_insert_iterator): Likewise.
(insert_iterator): Likewise. Remove NSDMIs.
(common_iterator): Constrain the default ctor.
(counted_iterator): Likewise.
* include/bits/stream_iterator.h (ostream_iterator): Remove the
default ctor.
* include/std/ranges (__detail::__box::operator=): Handle
self-assignment in the primary template.
(__detail::__box): In the partial specialization: adjust
constraints as per P2325. Add specialized operator= for the
case when the wrapped type is not copyable. Constrain the
default ctor. Avoid list-initialization.
(single_view): Constraint the default ctor.
(iota_view): Relax semiregular constraint to copyable.
Constrain the default ctor.
(iota_view::_Iterator): Constraint the default ctor.
(basic_istream_view): Remove the default ctor. Remove NSDMIs.
Remove redundant checks for empty _M_stream.
(basic_istream_view::_Iterator): Likewise.
(ref_view): Remove the default ctor. Remove NSDMIs.
(ref_view::_Iterator): Constrain the default ctor.
(__detail::__non_propagating_cache::operator=): Define overload
for assigning from a value of the underlying type.
(filter_view): Likewise.
(filter_view::_Iterator): Likewise.
(transform_view): Likewise.
(transform_view::_Iterator): Likewise.
(take_view): Likewise.
(take_view::_Iterator): Likewise.
(take_while_view): Likewise.
(take_while_view::_Iterator): Likewise.
(drop_while_view): Likewise.
(drop_while_view::_Iterator): Likewise.
(join_view): Likewise.
(split_view::_OuterIter::__current): Adjust after changing the
type of _M_current.
(split_view::_M_current): Wrap it in a __non_propagating_cache.
(split_view::split_view): Constrain the default ctor.
(common_view): Constrain the default ctor.
(reverse_view): Likewise.
(elements_view): Likewise.
* include/std/span (enable_view<span<_ElementType, _Extent>>):
Define this partial specialization to true unconditionally.
* include/std/version (__cpp_lib_ranges): Adjust value.
* testsuite/24_iterators/back_insert_iterator/constexpr.cc:
Don't attempt to default construct a back_insert_iterator.
* testsuite/24_iterators/front_insert_iterator/constexpr.cc:
Don't attempt to default construct a front_insert_iterator.
* testsuite/24_iterators/insert_iterator/constexpr.cc:
Don't attempt to default construct an insert_iterator.
* testsuite/24_iterators/ostream_iterator/requirements/constexpr.cc:
Remove this test for default constructibility of ostream_iterator.
* testsuite/std/ranges/97600.cc: Don't attempt to default
construct a basic_istream_view.
* testsuite/std/ranges/adaptors/detail/semiregular_box.cc:
Rename to ...
* testsuite/std/ranges/adaptors/detail/copyable_box.cc: ... this.
(test02): Adjust now that __box is copyable-box not
semiregular-box.
(test03): New test.
* testsuite/std/ranges/p2325.cc: New test.
* testsuite/std/ranges/single_view.cc (test06): New test.
* testsuite/std/ranges/view.cc: Adjust now that view doesn't
require default_initializable.
This removes the helper functions added by r8-1294 to detect whether the
char_traits member functions can be evaluated at compile time. Instead,
we can just use __builtin_constant_evaluated directly, which is well
supported by non-GCC compilers by now.
As a result, there is a chance that those members will no longer be
usable in constant expressions when using old versions of non-GCC
compilers. Make the relevant feature test macros depend on the
availability of __builtin_constant_evaluated, so they are defined only
when the feature is actualyl available.
The new testcase from the PR is added to the libitm testsuite, because
that's where we can be sure it's OK to use the -fgnu-tm option.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
PR libstdc++/91488
libstdc++-v3/ChangeLog:
* include/bits/basic_string.h (__cpp_lib_constexpr_string): Only
define when is_constant_evaluated is available.
* include/bits/char_traits.h (__cpp_lib_constexpr_char_traits):
Likewise.
(__constant_string_p, __constant_array_p): Remove.
(char_traits): Use is_constant_evaluated directly.
* include/std/version (__cpp_lib_constexpr_char_traits)
(__cpp_lib_constexpr_string): Only define when
is_constant_evaluated is available.
libitm/ChangeLog:
* testsuite/libitm.c++/libstdc++-pr91488.C: New test.
This force-enables perfect forwarding call wrapper semantics whenever
the extra arguments of a partially applied range adaptor aren't all
trivially copyable, so as to avoid incurring unnecessary copies of
potentially expensive-to-copy objects (such as std::function objects)
when invoking the adaptor.
PR libstdc++/100940
libstdc++-v3/ChangeLog:
* include/std/ranges (__adaptor::_Partial): For the "simple"
forwarding partial specializations, also require that
the extra arguments are trivially copyable.
* testsuite/std/ranges/adaptors/100577.cc (test04): New test.
