The _S_has_simple_extra_args mechanism is used to simplify forwarding
of range adaptor's extra arguments when perfect forwarding call wrapper
semantics isn't required for correctness, on a per-adaptor basis.
Both views::take and views::drop are flagged as such, but it turns out
perfect forwarding semantics are needed for these adaptors in some
contrived cases, e.g. when their extra argument is a move-only class
that's implicitly convertible to an integral type.
To fix this, we could just clear the flag for views::take/drop as with
views::split, but that'd come at the cost of acceptable diagnostics
for ill-formed uses of these adaptors (see PR100577).
This patch instead allows adaptors to parameterize their
_S_has_simple_extra_args flag according the types of the captured extra
arguments, so that we could conditionally disable perfect forwarding
semantics only when the types of the extra arguments permit it. We
then use this finer-grained mechanism to safely disable perfect
forwarding semantics for views::take/drop when the extra argument is
integer-like, rather than incorrectly always disabling it. Similarly,
for views::split, rather than always enabling perfect forwarding
semantics we now safely disable it when the extra argument is a scalar
or a view, and recover good diagnostics for these common cases.
PR libstdc++/100940
libstdc++-v3/ChangeLog:
* include/std/ranges (__adaptor::_RangeAdaptor): Document the
template form of _S_has_simple_extra_args.
(__adaptor::__adaptor_has_simple_extra_args): Add _Args template
parameter pack. Try to treat _S_has_simple_extra_args as a
variable template parameterized by _Args.
(__adaptor::_Partial): Pass _Arg/_Args to the constraint
__adaptor_has_simple_extra_args.
(views::_Take::_S_has_simple_extra_args): Templatize according
to the type of the extra argument.
(views::_Drop::_S_has_simple_extra_args): Likewise.
(views::_Split::_S_has_simple_extra_args): Define.
* testsuite/std/ranges/adaptors/100577.cc (test01, test02):
Adjust after changes to _S_has_simple_extra_args mechanism.
(test03): Define.
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.
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.
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.
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.
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.
The result of COMMON-REF(A&, B&&) where they have no common reference
type should not be a reference. The implementation of COMMON-REF fails
to check that the result is a reference, so is well-formed when it
shouldn't be. This means that common_reference uses that result when it
shouldn't.
The fix is to reject the result of COMMON-REF(A, B) if it's not a
reference, so that common_reference falls through to the next case,
which uses COND-RES, which yields a non-reference result.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/100894
* include/std/type_traits (__common_ref_impl<X&, Y&>): Only
use the type if it's a reference.
* testsuite/20_util/common_reference/100894.cc: New test.
The no_unique_address attribute is not a reserved name until C++20, so
to use it in C++11/14/17 modes we should use the __no_unique_address_
form. We already use that form when using the attribute, but not in the
__has_cpp_attribute check.
libstdc++-v3/ChangeLog:
PR libstdc++/101055
* include/std/tuple: Use reserved form of attribute name.
* testsuite/17_intro/headers/c++2011/all_attributes.cc: Add
check for no_unique_address.
* testsuite/17_intro/headers/c++2014/all_attributes.cc:
Likewise.
* testsuite/17_intro/headers/c++2017/all_attributes.cc:
Likewise.
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.
libstdc++-v3/ChangeLog:
PR libstdc++/100982
* include/std/optional (optional::operator=(const optional<U>&)):
Fix value category used in is_assignable check.
* testsuite/20_util/optional/assignment/100982.cc: New test.
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>.
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.
This is a remnant of poorly executed refactoring.
libstdc++-v3/ChangeLog:
* include/std/barrier (__tree_barrier::_M_arrive): Remove
unnecessary hasher instantiation.
We already have conditional noexcept so this just constrains the
non-member swap overload.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/experimental/propagate_const (swap): Constrain.
* testsuite/experimental/propagate_const/swap/lwg3413.cc: New test.
Clang complains about the missing typename. I believe it's not required
in a more complete implementation of C++, but it's nicer to support
less complete implementations.
PR libstdc++/100900
libstdc++-v3/ChangeLog:
* include/std/ranges (elements_view::__iter_cat::_S_iter_cat):
Add missing typename.
The operator<=>(const optional<T>&, const U&) operator is supposed to be
constrained with three_way_comparable_with<U, T> so that it can only be
used when T and U are weakly-equality-comparable and also three-way
comparable.
Adding that constrain completely breaks std::optional comparisons,
because it causes constraint recursion. To avoid that, an additional
check that U is not a specialization of std::optional is needed. That
appears to be a defect in the standard and should be reported to LWG.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/98842
* include/std/optional (operator<=>(const optional<T>& const U&)):
Add missing constraint and add workaround for template
recursion.
* testsuite/20_util/optional/relops/three_way.cc: Check that
type without equality comparison cannot be compared when wrapped
in std::optional.
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.
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.
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.
This significantly improves the performance of std::any_cast, by
avoiding an indirect call to the _S_manage function through a function
pointer. Before we make that indirect call we've already established
that the contained value has the expected type, which means we also know
the manager type, and so can call one of its members directly.
We also know the precise type in the any::emplace functions, because
we've just constructed that type, so we can use the new member there
too. That doesn't seem to affect performance, but we might as well use
the new _S_access function anyway.
Signed-off-by: Tim Adye <Tim.Adye@cern.ch>
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/any (any::_Manager::_S_access): New static
function to access the contained value.
(any::emplace, __any_caster): Use _S_access member of the
manager type.
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.
r11-8053 rewrote the range adaptor implementation in conformance with
P2281R1, making partial application act like a SFINAE-friendly perfect
forwarding call wrapper. Making SFINAE-friendliness coexist with
perfect forwarding here requires adding fallback deleted operator()
overloads (as described in e.g. section 5.5 of P0847R6). But
unfortunately, as reported in PR100577, this necessary technique of
using of deleted overloads regresses diagnostics for ill-formed calls to
partially applied range adaptors in GCC.
Although GCC's diagnostics can arguably be improved here by having the
compiler explain why the other candidates weren't viable when overload
resolution selects a deleted candidate, we can also largely work around
this on the library side (and achieve more concise diagnostics than by
a frontend-side improvement alone) if we take advantage of the
observation that not all range adaptors need perfect forwarding call
wrapper semantics, in fact only views::split currently needs it, because
all other range adaptors either take no extra arguments or only
arguments that are expected to be freely/cheaply copyable, e.g. function
objects and integer-like types. (The discussion section in P2281R1 goes
into detail about why views::split is special.)
To that end, this introduces opt-in flags for denoting a range adaptor
as having "simple" extra arguments (in the case of a range adaptor
non-closure) or having a "simple" call operator (in the case of a range
adaptor closure). These flags are then used to conditionally simplify
the operator() for the generic _Partial and _Pipe class templates, down
from needing three overloads thereof (including one defined as deleted)
to just needing a single overload. The end result is that diagnostic
quality is restored for all adaptors except for views::split, and
diagnostics for the adaptors are generally made more concise since
there's only a single _Partial/_Pipe overload to diagnose instead of
three of them.
libstdc++-v3/ChangeLog:
PR libstdc++/100577
* include/std/ranges (_RangeAdaptorClosure): Document
_S_has_simple_call_op mechanism.
(_RangeAdaptor): Document _S_has_simple_extra_args mechanism.
(__closure_has_simple_call_op): New concept.
(__adaptor_has_simple_extra_args): Likewise.
(_Partial<_Adaptor, _Args...>): New partial specialization.
(_Partial<_Adaptor, _Arg>): Likewise.
(_Pipe<_Lhs, _Rhs>): Likewise.
(views::_All::_S_has_simple_call_op): Define to true.
(views::_Filter::_S_has_simple_extra_args): Likewise.
(views::_Transform::_S_has_simple_extra_args): Likewise.
(views::_Take::_S_has_simple_extra_args): Likewise.
(views::_TakeWhile::_S_has_simple_extra_args): Likewise.
(views::_Drop::_S_has_simple_extra_args): Likewise.
(views::_DropWhile::_S_has_simple_extra_args): Likewise.
(views::_Join::_S_has_simple_call_op): Likewise.
(views::_Split): Document why we don't define
_S_has_simple_extra_args to true for this adaptor.
(views::_Common::_S_has_simple_call_op): Define to true.
(views::_Reverse::_S_has_simple_call_op): Likewise.
(views::_Elements::_S_has_simple_call_op): Likewise.
* testsuite/std/ranges/adaptors/100577.cc: New test.
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.
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.
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.
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.
This fixes two issues with our iterator caching as described in detail
in the PR. Since we recently added the __non_propagating_cache class
template as part of r12-336 for P2328, this patch just rewrites the
problematic _CachedPosition partial specialization in terms of this
class template.
For the offset partial specialization, it's safe to propagate the cached
offset on copy/move, but we should still invalidate the cached offset in
the source object on move.
libstdc++-v3/ChangeLog:
PR libstdc++/100479
* include/std/ranges (__detail::__non_propagating_cache): Move
definition up to before that of _CachedPosition. Make base
class _Optional_base protected instead of private. Add const
overload for operator*.
(__detail::_CachedPosition): Rewrite the partial specialization
for forward ranges as a derived class of __non_propagating_cache.
Remove the size constraint on the partial specialization for
random access ranges. Add copy/move/copy-assignment/move-assignment
members to the offset partial specialization for random
access ranges that propagate the cached value but additionally
invalidate it in the source object on move.
* testsuite/std/ranges/adaptors/100479.cc: New test.
libstdc++-v3/ChangeLog:
PR libstdc++/100690
* include/std/ranges (iota_view::_Sentinel::_M_distance_from):
Split out this member function from ...
(iota_view::_Sentinel::operator-): ... here, for sake of access
control.
* testsuite/std/ranges/iota/iota_view.cc (test05): New test.
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.
This implements the P0896R4 changes to reverse_iterator's member types
value_type, difference_type and reference in C++20 mode, which fixes
taking the reverse_iterator of an iterator with a non-integral
difference_type (such as iota_view<long long>).
libstdc++-v3/ChangeLog:
PR libstdc++/100639
* include/bits/stl_iterator.h (reverse_iterator::difference_type):
In C++20 mode, define in terms of iter_difference_t as per P0896R4.
(reverse_iterator::reference): Likewise, but with iter_reference_t.
(reverse_iterator::value_type): Likewise, but with iter_value_t.
* testsuite/std/ranges/adaptors/reverse.cc (test08): New test.
* testsuite/24_iterators/reverse_iterator/100639.cc: New test.
This patch conditionally disables the compilation of floating_to_chars.cc
on 16 bit targets, thus fixing a build failure for these targets as
the POW10_SPLIT_2 array exceeds the maximum object size.
libstdc++-v3/
PR libstdc++/100361
* include/std/charconv (to_chars): Hide the overloads for
floating-point types for 16 bit targets.
* src/c++17/floating_to_chars.cc: Don't compile for 16 bit targets.
* testsuite/20_util/to_chars/double.cc: Run this test only on
size32plus targets.
* testsuite/20_util/to_chars/float.cc: Likewise.
* testsuite/20_util/to_chars/long_double.cc: Likewise.
In the earlier commit r12-854 I forgot to also rewrite the other operator-
overload in terms of the split-out member function _M_distance_from.
libstdc++-v3/ChangeLog:
PR libstdc++/100631
* include/std/ranges (elements_view::_Sentinel::operator-): Use
_M_distance_from in the other operator- overload too.
* testsuite/std/ranges/adaptors/elements.cc (test06): Augment test.
This makes the in-place constructor of our partial specialization of
__box for already-semiregular types perform direct-non-list-initialization
(in accordance with the specification of the primary template), and
additionally makes the member function data() use std::__addressof.
libstdc++-v3/ChangeLog:
PR libstdc++/100475
* include/std/ranges (__box::__box): Use non-list-initialization
in member initializer list of in-place constructor of the
partial specialization for semiregular types.
(__box::operator->): Use std::__addressof.
* testsuite/std/ranges/adaptors/detail/semiregular_box.cc
(test02): New test.
* testsuite/std/ranges/single_view.cc (test04): New test.
A range being a random access range isn't a sufficient condition for
ranges::next(iter, sent) to have constant time complexity -- it must
also have a sized sentinel. This adjusts the memoization condition for
reverse_view accordingly.
libstdc++-v3/ChangeLog:
PR libstdc++/100621
* include/std/ranges (reverse_view::_S_needs_cached_begin):
Set to true if the underlying non-common random-access range
doesn't have a sized sentinel.
libstdc++-v3/ChangeLog:
PR libstdc++/100631
* include/std/ranges (elements_view::_Iterator): Also befriend
_Sentinel<!_Const>.
(elements_view::_Sentinel::_M_equal): Templatize.
(elements_view::_Sentinel::_M_distance_from): Split out from ...
(elements_view::_Sentinel::operator-): ... here. Depend on
_Base2 instead of _Base in the return type.
* testsuite/std/ranges/adaptors/elements.cc (test06, test07):
New tests.
Fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100334
libstdc++-v3/ChangeLog:
* include/bits/atomic_wait.h (__waiter::_M_do_wait_v): loop
until value change observed.
(__waiter_base::_M_laundered): New member.
(__waiter_base::_M_notify): Check _M_laundered to determine
whether to wake one or all.
(__detail::__atomic_compare): Return true if call to
__builtin_memcmp() == 0.
(__waiter_base::_S_do_spin_v): Adjust predicate.
* testsuite/29_atomics/atomic/wait_notify/100334.cc: New
test.
The constraint check for filesystem::path construction uses
decltype(__is_path_src(declval<Source>())) which mean it considers
conversion from an rvalue. When Source is a volatile-qualified type
it cannot use is_path_src(const Unknown&) because a const lvalue
reference can only bind to a non-volatile rvalue.
Since the relevant path members all have a const Source& parameter,
the constraint should be defined in terms of declval<const Source&>(),
not declval<Source>(). This avoids the problem of volatile-qualified
rvalues, because we no longer use an rvalue at all.
libstdc++-v3/ChangeLog:
PR libstdc++/100630
* include/experimental/bits/fs_path.h (__is_constructible_from):
Test construction from a const lvalue, not an rvalue.
* testsuite/27_io/filesystem/path/construct/100630.cc: New test.
* testsuite/experimental/filesystem/path/construct/100630.cc:
New test.
This patch provides better diagnostics for common misuse of
[locale.convenience] functions with std::string as a character type.
libstdc++-v3/ChangeLog:
PR libstdc++/89728
* include/bits/locale_facets.h (ctype<basic_string<C,T,A>>):
Declare (but do not define) partial specialization.
* testsuite/22_locale/ctype/is/string/89728_neg.cc: New test.
The changes in 75c6a925da were slightly
incorrect, because the converting constructor should be noexcept, and
the POCMA and is_always_equal traits should still be present in C++20.
This fixes it, and slightly refactors the preprocessor conditions and
order of members. Also add comments explaining things.
The non-standard construct and destroy members added for PR 78052 can be
private if allocator_traits<allocator<void>> is made a friend.
libstdc++-v3/ChangeLog:
* include/bits/allocator.h (allocator<void>) [C++20]: Add
missing noexcept to constructor. Restore missing POCMA and
is_always_equal_traits.
[C++17]: Make construct and destroy members private and
declare allocator_traits as a friend.
* include/bits/memoryfwd.h (allocator_traits): Declare.
* include/ext/malloc_allocator.h (malloc_allocator::allocate):
Add nodiscard attribute. Add static assertion for LWG 3307.
* include/ext/new_allocator.h (new_allocator::allocate): Add
static assertion for LWG 3307.
* testsuite/20_util/allocator/void.cc: Check that converting
constructor is noexcept. Check for propagation traits and
size_type and difference_type. Check that pointer and
const_pointer are gone in C++20.
We have a comment saying to replace the simple binary_semaphore type
with std::binary_semaphore, which has been done. However, that isn't
defined on all targets. So keep the simple one here that just implements
the parts of the API needed by <stop_token>, and remove the comment
suggesting it should be replaced.
libstdc++-v3/ChangeLog:
* include/std/stop_token: Remove TODO comment.
This has been tentatively approved by LWG. The deleter from a unique_ptr
can be moved into the shared_ptr (at least, since LWG 2802). This uses
std::forward<_Del>(__r.get_deleter()) not std::move(__r.get_deleter())
because we don't want to convert the deleter to an rvalue when _Del is
an lvalue reference type.
This also adds a missing is_move_constructible_v<D> constraint to the
shared_ptr(unique_ptr<Y, D>&&) constructor, which is inherited from the
shared_ptr(Y*, D) constructor due to the use of "equivalent to" in the
specified effects.
libstdc++-v3/ChangeLog:
* include/bits/shared_ptr_base.h (__shared_count(unique_ptr&&)):
Initialize a non-reference deleter from an rvalue, as per LWG
3548.
(__shared_ptr::_UniqCompatible): Add missing constraint.
* testsuite/20_util/shared_ptr/cons/lwg3548.cc: New test.
* testsuite/20_util/shared_ptr/cons/unique_ptr_deleter.cc: Check
constraints.
