4612 Commits

Author SHA1 Message Date
Jonathan Wakely
aca7a0253d libstdc++: Use std::addressof in ranges::uninitialized_xxx [PR101571]
Make the ranges::uninitialized_xxx algorithms use std::addressof to
protect against iterator types that overload operator&.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/101571
	* include/bits/ranges_uninitialized.h (_DestroyGuard): Change
	constructor parameter to reference and use addressof.
	* testsuite/util/testsuite_iterators.h: Define deleted operator&
	overloads for test iterators.
2021-07-22 14:37:24 +01:00
Jonathan Wakely
c22bcfd2f7 libstdc++: Initialize all subobjects of std::function
The std::function::swap member swaps each data member unconditionally,
resulting in -Wmaybe-uninitialized warnings for a default constructed
object. This happens because the _M_invoker and _M_functor members are
only initialized if the function has a target.

This change ensures that all subobjects are zero-initialized on
construction.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/std_function.h (_Function_base): Add
	default member initializers and define constructor as defaulted.
	(function::_M_invoker): Add default member initializer.
2021-07-22 13:53:57 +01:00
Jonathan Wakely
89ec3b67db libstdc++: fix is_default_constructible for hash containers [PR 100863]
The recent change to _Hashtable_ebo_helper for this PR broke the
is_default_constructible trait for a hash container with a non-default
constructible allocator. That happens because the constructor needs to
be user-provided in order to initialize the member, and so is not
defined as deleted when the type is not default constructible.

By making _Hashtable derive from _Enable_special_members we can ensure
that the default constructor for the std::unordered_xxx containers is
deleted when it would be ill-formed. This makes the trait give the
correct answer.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/100863
	* include/bits/hashtable.h (_Hashtable): Conditionally delete
	default constructor by deriving from _Enable_special_members.
	* testsuite/23_containers/unordered_map/cons/default.cc: New test.
	* testsuite/23_containers/unordered_set/cons/default.cc: New test.
2021-07-20 16:22:26 +01:00
Jonathan Wakely
bfb0586ebd libstdc++: Simplify numeric_limits<__max_size_type>
If __int128 is supported then __int_traits<__int128> is guaranteed to be
specialized, so we can remove the preprocessor condition inside the
std::numeric_traits<__detail::__max_size_type> specialization. Simply
using __int_traits<_Sp::__rep> gives the right answer.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/max_size_type.h (numeric_limits<__max_size_type>):
	Use __int_traits unconditionally.
2021-07-16 15:03:03 +01:00
Jonathan Wakely
95891ca020 libstdc++: Modernize <bits/random.h> helpers
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/random.h (_Shift::__value): Use constexpr.
	(_Select_uint_least_t::type): Use using-declaration.
	(_Mod): Likewise.
	* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error
	line number.
2021-07-16 15:03:03 +01:00
Jonathan Wakely
42167831ab libstdc++: Use __extension__ instead of diagnostic pragmas
This reverts c1676651b6c417e8f2b276a28199d76943834277 and uses the
__extension__ keyword to prevent pedantic warnings instead of diagnostic
pragmas.

This also adds the __extension__ keyword in <limits> and <bits/random.h>
where there are some more warnings that I missed in the previous commit.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/cpp_type_traits.h (__INT_N): Use __extension__
	instead of diagnostic pragmas.
	* include/bits/functional_hash.h: Likewise.
	* include/bits/iterator_concepts.h (__is_signed_int128)
	(__is_unsigned_int128): Likewise.
	* include/bits/max_size_type.h (__max_size_type): Likewise.
	(numeric_limits<__max_size_type>): Likewise.
	* include/bits/std_abs.h (abs): Likewise.
	* include/bits/stl_algobase.h (__size_to_integer): Likewise.
	* include/bits/uniform_int_dist.h (uniform_int_distribution):
	Likewise.
	* include/ext/numeric_traits.h (_GLIBCXX_INT_N_TRAITS):
	Likewise.
	* include/std/type_traits (__is_integral_helper<INT_N>)
	(__is_signed_integer, __is_unsigned_integer)
	(__make_unsigned<INT_N>, __make_signed<INT_N>): Likewise.
	* include/std/limits (__INT_N): Add __extension__ keyword.
	* include/bits/random.h (_Select_uint_least_t)
	(random_device): Likewise.
2021-07-16 15:03:03 +01:00
Jonathan Wakely
adc03d72c3 libstdc++: Adjust doxygen markup for unique_ptr grouping
This reorders the @{ and @relates tags, and moves the definition of the
__cpp_lib_make_unique macro out of the group, as it seems to confuse
doxygen.

libstdc++-v3/ChangeLog:

	* include/bits/unique_ptr.h: Adjust doxygen markup.
2021-07-16 08:40:44 +01:00
Jonathan Wakely
c1676651b6 libstdc++: Suppress pedantic warnings about __int128
With -std=c++NN -pedantic -Wsystem-headers there are warnings about the
use of __int128, which can be suppressed using diagnostic pragmas.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/cpp_type_traits.h: Add diagnostic pragmas around
	uses of non-standard integer types.
	* include/bits/functional_hash.h: Likewise.
	* include/bits/iterator_concepts.h: Likewise.
	* include/bits/max_size_type.h: Likewise.
	* include/bits/std_abs.h: Likewise.
	* include/bits/stl_algobase.h: Likewise.
	* include/bits/uniform_int_dist.h: Likewise.
	* include/ext/numeric_traits.h: Likewise.
	* include/std/type_traits: Likewise.
2021-07-16 08:40:43 +01:00
Jonathan Wakely
1f7182d68c libstdc++: Add noexcept to __replacement_assert [PR101429]
This results in slightly smaller code when assertions are enabled when
either using Clang (because it adds code to call std::terminate when
potentially-throwing functions are called in a noexcept function) or a
freestanding or non-verbose build (because it doesn't use printf).

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/101429
	* include/bits/c++config (__replacement_assert): Add noexcept.
	[!_GLIBCXX_VERBOSE] (__glibcxx_assert_impl): Use __builtin_trap
	instead of __replacement_assert.
2021-07-15 16:25:42 +01:00
Jonathan Wakely
bc8f0ed704 libstdc++: Revert changes to std::unique_ptr<T[]>::operator[] [PR 101271]
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[].
2021-07-02 12:15:28 +01:00
Jonathan Wakely
f2ce64b53f libstdc++: Improvements to Doxygen markup
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.
2021-07-01 18:45:48 +01:00
Jonathan Wakely
6963c3b9ed libstdc++: Improve Doxygen documentation groups [PR 101258]
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.
2021-07-01 00:25:46 +01:00
Jonathan Wakely
996be6b670 libstdc++: Suppress redundant definitions of static members in <random>
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.
2021-07-01 00:15:29 +01:00
Jonathan Wakely
084635aa80 libstdc++: Remove redundant explicit instantiations
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.
2021-06-28 15:16:08 +01:00
Jonathan Wakely
b7a89c041a libstdc++: Allow unique_ptr<Incomplete[]>::operator[] [PR 101236]
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.
2021-06-28 14:20:55 +01:00
Jonathan Wakely
e5c422b7d8 libstdc++: Implement LWG 415 for std::ws
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.
2021-06-28 13:34:49 +01:00
Jonathan Wakely
4a52cf2eb9 libstdc++: Avoid intercepting exception in ostream::write
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.
2021-06-25 18:47:44 +01:00
Jonathan Wakely
f8c5b542f6 libstdc++: Implement LWG 581 for std:ostream::flush()
LWG 581 changed ostream::flush() to an unformatted output function for
C++11, but it was never implemented in libstdc++.

libstdc++-v3/ChangeLog:

	* doc/xml/manual/intro.xml: Document LWG 581 change.
	* doc/html/manual/bugs.html: Regenerate.
	* include/bits/basic_ios.tcc: Whitespace.
	* include/bits/ostream.tcc (basic_ostream::flush()): Construct
	sentry.
	* testsuite/27_io/basic_ostream/flush/char/2.cc: Check
	additional cases.
	* testsuite/27_io/basic_ostream/flush/char/exceptions_badbit_throw.cc:
	Likewise.
	* testsuite/27_io/basic_ostream/flush/wchar_t/2.cc: Likewise.
	* testsuite/27_io/basic_ostream/flush/wchar_t/exceptions_badbit_throw.cc:
	Likewise.
2021-06-25 18:47:39 +01:00
Jonathan Wakely
9b6c65c754 libstdc++: Fix exception handling in std::ostream seek functions
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.
2021-06-25 18:47:23 +01:00
Jonathan Wakely
17bc3848e0 libstdc++: Implement LWG 2762 for std::unique_ptr::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.
2021-06-24 14:04:02 +01:00
Jonathan Wakely
6c63cb231e libstdc++: Implement LWG 3422 for std::seed_seq
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.
2021-06-22 20:58:25 +01:00
Thomas Rodgers
e02840c1a9 libstdc++: Fix for deadlock in std::counting_semaphore [PR100806]
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.
2021-06-22 11:06:07 -07:00
Patrick Palka
12bdd39755 libstdc++: Sync __cpp_lib_ranges macro defined in ranges_cmp.h
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.
2021-06-21 09:45:31 -04:00
Patrick Palka
4123650bd0 libstdc++: Implement LWG 3546 changes to common_iterator
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.
2021-06-18 20:50:13 -04:00
Patrick Palka
cc9c94d43d libstdc++: Reduce ranges::minmax/minmax_element comparison complexity
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.
2021-06-18 19:33:39 -04:00
Patrick Palka
2786064d91 libstdc++: Move ranges algos used by <ranges> into ranges_util.h
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.
2021-06-17 22:44:41 -04:00
Patrick Palka
4b4f5666b4 libstdc++: Implement P2325 changes to default-constructibility of views
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.
2021-06-17 22:29:03 -04:00
Jonathan Wakely
b376b1ef38 libstdc++: Simplify constexpr checks in std::char_traits [PR 91488]
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.
2021-06-17 22:00:58 +01:00
Jonathan Wakely
c25e3bf879 libstdc++: Use named struct for __decay_copy
In r12-1486-gcb326a6442f09cb36b05ce556fc91e10bfeb0cf6 I changed
__decay_copy to be a function object of unnamed class type. This causes
problems when importing the library headers:

error: conflicting global module declaration 'constexpr const std::ranges::__cust_access::<unnamed struct> std::ranges::__cust_access::__decay_copy'

The fix is to use a named struct instead of an anonymous one.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/iterator_concepts.h (__decay_copy): Name type.
2021-06-16 14:31:13 +01:00
Jonathan Wakely
b9e35ee6d6 libstdc++: Revert final/non-addressable changes to ranges CPOs
In r12-1489-g8b93548778a487f31f21e0c6afe7e0bde9711fc4 I made the
[range.access] CPO types final and non-addressable. Tim Song pointed out
this is wrong. Only the [range.iter.ops] functions should be final and
non-addressable. Revert the changes to the [range.access] objects.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/ranges_base.h (ranges::begin, ranges::end)
	(ranges::cbegin, ranges::cend, ranges::rbeing, ranges::rend)
	(ranges::crbegin, ranges::crend, ranges::size, ranges::ssize)
	(ranges::empty, ranges::data, ranges::cdata): Remove final
	keywords and deleted operator& overloads.
	* testsuite/24_iterators/customization_points/iter_move.cc: Use
	new is_customization_point_object function.
	* testsuite/24_iterators/customization_points/iter_swap.cc:
	Likewise.
	* testsuite/std/concepts/concepts.lang/concept.swappable/swap.cc:
	Likewise.
	* testsuite/std/ranges/access/begin.cc: Likewise.
	* testsuite/std/ranges/access/cbegin.cc: Likewise.
	* testsuite/std/ranges/access/cdata.cc: Likewise.
	* testsuite/std/ranges/access/cend.cc: Likewise.
	* testsuite/std/ranges/access/crbegin.cc: Likewise.
	* testsuite/std/ranges/access/crend.cc: Likewise.
	* testsuite/std/ranges/access/data.cc: Likewise.
	* testsuite/std/ranges/access/empty.cc: Likewise.
	* testsuite/std/ranges/access/end.cc: Likewise.
	* testsuite/std/ranges/access/rbegin.cc: Likewise.
	* testsuite/std/ranges/access/rend.cc: Likewise.
	* testsuite/std/ranges/access/size.cc: Likewise.
	* testsuite/std/ranges/access/ssize.cc: Likewise.
	* testsuite/util/testsuite_iterators.h
	(is_customization_point_object): New function.
2021-06-16 14:31:04 +01:00
Jonathan Wakely
8b93548778 libstdc++: Make ranges CPOs final and not addressable
This restricts the API of the CPOs and other function objects so they
cannot be misused by deriving from them or taking their addresses.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/ranges_base.h (ranges::begin, ranges::end)
	(ranges::cbegin, ranges::cend, ranges::rbeing, ranges::rend)
	(ranges::crbegin, ranges::crend, ranges::size, ranges::ssize)
	(ranges::empty, ranges::data, ranges::cdata): Make types final.
	Add deleted operator& overloads.
	(ranges::advance, ranges::distance, ranges::next, ranges::prev):
	Likewise.
	* testsuite/std/ranges/headers/ranges/synopsis.cc: Replace
	ill-formed & expressions with using-declarations. Add checks for
	other function objects.
2021-06-15 18:20:06 +01:00
Jonathan Wakely
9245b0e84c libstdc++: Add noexcept specifiers to some range adaptors
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/ranges_util.h (view_interface): Add noexcept to
	empty, operator bool, data and size members.
	(subrange): Add noexcept to constructors.
	* include/std/ranges (single_view, ref_view): Add noexcept to
	constructors.
	(views::single, views::all): Add noexcept.
	* testsuite/std/ranges/adaptors/all.cc: Check noexcept.
	* testsuite/std/ranges/single_view.cc: Likewise.
2021-06-15 18:20:06 +01:00
Jonathan Wakely
a88fc03ba7 libstdc++: Remove precondition checks from ranges::subrange
The assertion in the subrange constructor causes semantic changes,
because the call to ranges::distance performs additional operations that
are not part of the constructor's specification. That will fail to
compile if the iterator is move-only, because the argument to
ranges::distance is passed by value. It will modify the subrange if the
iterator is not a forward iterator, because incrementing the copy also
affects the _M_begin member. Those problems could be prevented by using
if-constexpr to only do the assertion for copyable forward iterators,
but the call to ranges::distance can also prevent the constructor being
usable in constant expressions. If the member initializers are usable in
constant expressions, but iterator increments of equality comparisons
are not, then the checks done by __glibcxx_assert might
make constant evaluation fail.

This change removes the assertion. Additionally, a new typedef is
introduced to simplify the declarations using __make_unsigned_like_t on
the iterator's difference type.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/ranges_util.h (subrange): Add __size_type typedef
	and use it to simplify declarations.
	(subrange(i, s, n)): Remove assertion.
	* testsuite/std/ranges/subrange/constexpr.cc: New test.
2021-06-15 18:20:06 +01:00
Jonathan Wakely
cb326a6442 libstdc++: Use function object for __decay_copy helper
By changing __cust_access::__decay_copy from a function template to a
function object we avoid ADL. That means it's fine to call it
unqualified (the compiler won't waste time doing ADL in associated
namespaces, and won't try to complete associated types).

This also makes some other minor simplications to other concepts for the
[range.access] CPOs.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/iterator_concepts.h (__cust_access::__decay_copy):
	Replace with function object.
	(__cust_access::__member_begin, ___cust_access::_adl_begin): Use
	__decay_copy unqualified.
	* include/bits/ranges_base.h (__member_end, __adl_end):
	Likewise. Use __range_iter_t for type of ranges::begin.
	(__member_rend): Use correct value category for rbegin argument.
	(__member_data): Use __decay_copy unqualified.
	(__begin_data): Use __range_iter_t for type of ranges::begin.
2021-06-15 18:20:06 +01:00
Jonathan Wakely
f9598d89a9 libstdc++: Fix noexcept-specifier for ranges::empty
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/ranges_base.h (ranges::empty): Check whether
	conversion to bool can throw.
	* testsuite/std/ranges/access/empty.cc: Check for correct
	noexcept-specifier.
2021-06-14 23:13:16 +01:00
Jonathan Wakely
1e690757d3 libstdc++: Fix filesystem::path comparisons for C++23
In C++23 there is a basic_string_view(Range&&) constructor, which is
constrained to take a range (specifically, a contiguous_range). When the
filesystem::path comparison operators call lhs.compare(rhs) the overload
taking a string_view is considered, which means checking whether path
satisfies the range concept. That satisfaction result changes depending
whether path::iterator is complete, which is ill-formed; no diagnostic
required. To avoid the problem, this change ensures that the overload
resolution is performed in a context where path::iterator is complete
and the range concept is satisfied. (The result of overload resolution
is always that the compare(const path&) overload is the best match, but
we still have to consider the compare(basic_string_view<value_type>) one
to decide if it even participates in overload resolution).

For std::filesystem::path we can't define the comparison operators later
in the file, because they are hidden friends, so a new helper is
introduced that gets defined when everything else is complete.

For std::experimental::filesystem::path we can just move the definitions
of the comparison operators later in the file.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/fs_path.h (operator==, operator<=>): Use new
	_S_compare function.
	(path::_S_compare): New function to call path::compare in a
	context where path::iterator is complete.
	* include/experimental/bits/fs_path.h (operator<, operator==):
	Define after path::iterator is complete.
	* testsuite/27_io/filesystem/path/native/conv_c++23.cc: New
	test.
	* testsuite/experimental/filesystem/path/native/conv_c++23.cc:
	New test.
2021-06-11 19:18:11 +01:00
Jonathan Wakely
5bfcfe3087 libstdc++: Add warnings for some C++23 deprecations
LWG 3036 deprecates std::pmr::polymorphic_allocator<T>::destroy in
favour of the equivalent member of std::allocator_traits.

LWG 3170 deprecates std::allocator<T>::is_always_equal in favour of
the equivalent member of std::allocator_traits.

This also updates a comment to note that we support the LWG 3541 change
(even before the issue was opened).

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/allocator.h (allocator::is_always_equal): Deprecate.
	* include/bits/iterator_concepts.h (indirectly_readable_traits):
	Add LWG issue number to comment.
	* include/std/memory_resource (polymorphic_allocator::release):
	Deprecate.
	* testsuite/20_util/allocator/requirements/typedefs.cc: Add
	dg-warning for deprecation. Also check std::allocator<void>.
2021-06-09 10:32:43 +01:00
Thomas Rodgers
25e5ecdf82 libstdc++: Fix Wrong param type in :atomic_ref<_Tp*>::wait [PR100889]
libstdc++-v3/ChangeLog:

	PR libstdc++/100889
	* include/bits/atomic_base.h (atomic_ref<_Tp*>::wait):
	Change parameter type from _Tp to _Tp*.
	* testsuite/29_atomics/atomic_ref/wait_notify.cc: Extend
	coverage of types tested.
2021-06-08 15:55:10 -07:00
Jonathan Wakely
96963713f6 libstdc++: Fix return type of ranges::ssize for 128-bit integer [PR 100824]
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/100824
	* include/bits/ranges_base.h (_SSize): Return signed type.
	* testsuite/std/ranges/access/ssize.cc: Check with __int128.
2021-06-05 11:44:51 +01:00
Jonathan Wakely
621ea10ca0 libstdc++: Implement LWG 3403 for std::ranges::ssize
I already changed the constraints for ranges::ssize to use ranges::size,
this implements the rest of LWG 3403, so that the returned type is the
signed type corresponding to the result of ranges::size.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/ranges_base.h (_SSize): Return the result of
	ranges::size converted to the wider of make-signed-like-t<S> and
	ptrdiff_t, rather than the ranges different type.
	* testsuite/std/ranges/access/ssize.cc: Adjust expected result
	for an iota_view that uses an integer class type for its
	difference_type.
2021-06-04 21:33:59 +01:00
Jonathan Wakely
3e5f2425f8 libstdc++: Fix helper concept for ranges::data [PR 100824]
We need to decay the result of t.data() before checking if it's a
pointer.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/100824
	* include/bits/ranges_base.h (__member_data): Use __decay_copy.
	* testsuite/std/ranges/access/data.cc: Add testcase from PR.
2021-06-04 21:33:53 +01:00
Jonathan Wakely
ee9548b36a libstdc++: Fix value categories used by ranges access CPOs [PR 100824]
The implementation of P2091R0 was incomplete, so that some range access
CPOs used perfect forwarding where they should not. This fixes it by
consistently operating on lvalues.

Some additional changes that are not necessary to fix the bug:

Modify the __as_const helper to simplify its usage. Instead of deducing
the value category from its argument, and requiring callers to forward
the argument as the correct category, add a non-deduced template
parameter which is used for the value category and accept the argument
as an lvalue. This means callers say __as_const<T>(t) instead of
__as_const(std::forward<T>(t)).

Always use an lvalue reference type as the template argument for the
_S_noexcept helpers, so that we only instantiate one specialization for
lvalues and rvalues of the same type.

Move some helper concepts and functions from namespace std::__detail
to ranges::__cust_access, to be consistent with the ranges::begin CPO.
This ensures that the __adl_begin concept and the _Begin::operator()
function are in the same namespace, so unqualified lookup is consistent
and the poison pills for begin are visible to both.

Simplified static assertions for arrays, because the expression a+0 is
already ill-formed for an array of incomplete type.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/100824
	* include/bits/iterator_concepts.h (__detail::__decay_copy)
	(__detail::__member_begin, __detail::__adl_begin): Move to
	namespace ranges::__cust_access.
	(__detail::__ranges_begin): Likewise, and rename to __begin.
	Remove redundant static assertion.
	* include/bits/ranges_base.h (_Begin, _End, _RBegin, _REnd):
	Use lvalue in noexcept specifier.
	(__as_const): Add non-deduced parameter for value category.
	(_CBegin, _CEnd, _CRBegin, _CREnd, _CData): Adjust uses of
	__as_const.
	(__member_size, __adl_size, __member_empty, __size0_empty):
	(__eq_iter_empty, __adl_data): Use lvalue objects in
	requirements.
	(__sentinel_size): Likewise. Add check for conversion to
	unsigned-like.
	(__member_data): Allow non-lvalue types to satisfy the concept,
	but use lvalue object in requirements.
	(_Size, _SSize): Remove forwarding to always use an lvalue.
	(_Data): Likewise. Add static assertion for arrays.
	* testsuite/std/ranges/access/cdata.cc: Adjust expected
	behaviour for rvalues. Add negative tests for ill-formed
	expressions.
	* testsuite/std/ranges/access/data.cc: Likewise.
	* testsuite/std/ranges/access/empty.cc: Adjust expected
	behaviour for rvalues.
	* testsuite/std/ranges/access/size.cc: Likewise.
2021-06-04 15:59:38 +01:00
Jonathan Wakely
f78f25f438 libstdc++: Add feature test macro for heterogeneous lookup in unordered containers
Also update the C++20 status docs.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* doc/xml/manual/status_cxx2020.xml:
	* doc/html/*: Regenerate.
	* include/bits/hashtable.h (__cpp_lib_generic_unordered_lookup):
	Define.
	* include/std/version (__cpp_lib_generic_unordered_lookup):
	Define.
	* testsuite/23_containers/unordered_map/operations/1.cc: Check
	feature test macro.
	* testsuite/23_containers/unordered_set/operations/1.cc:
	Likewise.
2021-06-04 15:59:37 +01:00
Patrick Palka
0614bbbe59 libstdc++: Avoid hard error in ranges::unique_copy [PR100770]
Here, in the constexpr if condition within ranges::unique_copy, when
input_iterator<_Out> isn't satisfied we must avoid substituting into
iter_value_t<_Out> because the latter isn't necessarily well-formed
then.  To that end, this patch factors out the condition into a concept
and uses it throughout.

This patch also makes the definition of our testsuite
output_iterator_wrapper more minimal by setting its value_type, pointer
and reference member types to void.  This means our existing tests for
unique_copy already exercise the fix for this bug, so we don't need
to add another test.  The only other fallout of this testsuite iterator
change appears in std/ranges/range.cc, where the use of range_value_t
on a test_output_range is now ill-formed.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_algo.h (__detail::__can_reread_output):
	Factor out this concept from ...
	(__unique_copy_fn::operator()): ... here.  Use the concept
	throughout.
	* testsuite/std/ranges/range.cc: Remove now ill-formed use
	of range_value_t on an output_range.
	* testsuite/util/testsuite_iterators.h (output_iterator_wrapper):
	Define value_type, pointer and reference member types to void.
2021-06-03 12:30:29 -04:00
Jonathan Wakely
f8f0193b5b libstdc++: Value-initialize objects held by EBO helpers [PR 100863]
The allocator, hash function and equality function should all be
value-initialized by the default constructor of an unordered container.
Do it in the EBO helper, so we don't have to get it right in multiple
places.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/100863
	PR libstdc++/65816
	* include/bits/hashtable_policy.h (_Hashtable_ebo_helper):
	Value-initialize subobject.
	* testsuite/23_containers/unordered_map/allocator/default_init.cc:
	Remove XFAIL.
	* testsuite/23_containers/unordered_set/allocator/default_init.cc:
	Remove XFAIL.
2021-06-02 13:33:41 +01:00
Jonathan Wakely
d832629169 libstdc++: Fix return value of std::ranges::advance [PR 100833]
The three-argument form of ranges::advance is supposed to return the
difference between the second argument and the distance the iterator was
advanced. When a non-random-access iterator is not advanced (because it
already equals the sentinel) we were returning 0 rather than n - 0.

libstdc++-v3/ChangeLog:

	PR libstdc++/100833
	* include/bits/ranges_base.h (ranges::advance(iter, n, sentinel)):
	Fix return value for no-op case.
	* testsuite/24_iterators/range_operations/advance.cc: Test
	return values of three-argument overload.
2021-06-01 17:09:06 +01:00
Jonathan Wakely
a49a045b92 libstdc++: Change [range.iter.op] functions to function objects [PR 100768]
The standard specifies std::ranges::distance etc as function templates,
but it also requires them to not be found by ADL, and to suppress ADL
when normal unqualified lookup does find them. That means they need to
be function objects.

libstdc++-v3/ChangeLog:

	PR libstdc++/100768
	* include/bits/ranges_base.h (advance, distance, next, prev):
	Replace function templates with function objects.
	* testsuite/24_iterators/headers/iterator/synopsis_c++20.cc:
	Adjust for changes to function objects.
	* testsuite/std/ranges/adaptors/elements.cc: Add using
	declarations for names from namespace ranges.
	* testsuite/std/ranges/adaptors/transform.cc: Likewise.
	* testsuite/24_iterators/range_operations/100768.cc: New test.
2021-05-26 19:15:34 +01:00
François Dumont
2c43f5ec9d libstdc++: Limit allocation on iterator insertion in Hashtable [PR 96088]
When inserting into unordered_multiset or unordered_multimap first instantiate
the node to store and compute the hash code from it to avoid a potential
intermediate key_type instantiation.

When inserting into unordered_set or unordered_map check if invoking the hash
functor with container key_type is noexcept and invoking the same hash functor
with key part of the iterator value_type can throw. In this case create a
temporary key_type instance at Hashtable level and use it to compute the hash
code. This temporary instance is moved to the final storage location if needed.

libstdc++-v3/ChangeLog:

	PR libstdc++/96088
	* include/bits/hashtable_policy.h (_Select2nd): New.
	(_NodeBuilder<>): New.
	(_ReuseOrAllocNode<>::operator()): Use variadic template args.
	(_AllocNode<>::operator()): Likewise.
	* include/bits/hashtable.h
	(_Hashtable<>::__node_builder_t): New.
	(_Hashtable<>::_M_insert_unique<>(_Kt&&, _Arg&&, const _NodeGenerator&)):
	 New.
	(_Hashtable<>::_S_forward_key): New.
	(_Hashtable<>::_M_insert): Use latter.
	(_Hashtable<>::_M_insert(const_iterator, _Arg&&, const _NodeGenerator&, false_type)):
	Instantiate node first, compute hash code second.
	* testsuite/23_containers/unordered_map/96088.cc: New test.
	* testsuite/23_containers/unordered_multimap/96088.cc: New test.
	* testsuite/23_containers/unordered_multiset/96088.cc: New test.
	* testsuite/23_containers/unordered_set/96088.cc: New test.
	* testsuite/util/replacement_memory_operators.h
	(counter::_M_increment): New.
	(counter::_M_decrement): New.
	(counter::reset()): New.
2021-05-24 21:51:06 +02:00
Jonathan Wakely
64ba45c76e libstdc++: Do not use static_assert without message in C++11
libstdc++-v3/ChangeLog:

	* include/bits/random.tcc (__representable_as_double)
	(__p1_representable_as_double): Add "" to static asserts.
2021-05-20 21:12:15 +01:00
Jonathan Wakely
6b42b5a8a2 libstdc++: Use __builtin_unreachable for constexpr assertions [PR 100676]
The current implementation of compile-time precondition checks causes
compilation to fail by calling a non-constexpr function declared at
block scope. This breaks the CUDA compiler, which wraps some libstdc++
headers in a pragma that declares everything as a __host__ __device__
function, but others are not wrapped and so everything is a __host__
function. The local declaration thus gets redeclared as two different
types of function, which doesn't work.

Just use __builtin_unreachable to make constant evaluation fail, instead
of the local function declaration. Also simplify the assertion macros,
which has the side effect of giving simpler compilation errors when
using Clang.

libstdc++-v3/ChangeLog:

	PR libstdc++/100676
	* include/bits/c++config (__glibcxx_assert_1): Rename to ...
	(__glibcxx_constexpr_assert): ... this.
	(__glibcxx_assert_impl): Use __glibcxx_constexpr_assert.
	(__glibcxx_assert): Define as either __glibcxx_constexpr_assert
	or __glibcxx_assert_impl.
	(__glibcxx_assert_2): Remove
	* include/debug/macros.h (_GLIBCXX_DEBUG_VERIFY_AT_F): Use
	__glibcxx_constexpr_assert instead of __glibcxx_assert_1.
	* testsuite/21_strings/basic_string_view/element_access/char/back_constexpr_neg.cc:
	Adjust expected error.
	* testsuite/21_strings/basic_string_view/element_access/char/constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/char/front_constexpr_neg.cc:
	Likewise.
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/back_constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr_neg.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/element_access/wchar_t/front_constexpr_neg.cc:
	Likewise.
	* testsuite/23_containers/span/back_neg.cc: Likewise.
	* testsuite/23_containers/span/front_neg.cc: Likewise.
	* testsuite/23_containers/span/index_op_neg.cc: Likewise.
2021-05-20 20:49:57 +01:00