This attempts to make is_nothrow_constructible more robust (and
efficient to compile) by not depending on is_constructible. Instead the
__is_constructible intrinsic is used directly. The helper class
__is_nt_constructible_impl which checks whether the construction is
non-throwing now takes a bool template parameter that is substituted by
the result of the instrinsic. This fixes the reported bug by not using
the already-instantiated (and incorrect) value of std::is_constructible.
I don't think it really fixes the problem in general, because
std::is_nothrow_constructible itself could already have been
instantiated in a context where it gives the wrong result. A proper fix
needs to be done in the compiler.
PR libstdc++/94033
* include/std/type_traits (__is_nt_default_constructible_atom): Remove.
(__is_nt_default_constructible_impl): Remove.
(__is_nothrow_default_constructible_impl): Remove.
(__is_nt_constructible_impl): Add bool template parameter. Adjust
partial specializations.
(__is_nothrow_constructible_impl): Replace class template with alias
template.
(is_nothrow_default_constructible): Derive from alias template
__is_nothrow_constructible_impl instead of
__is_nothrow_default_constructible_impl.
* testsuite/20_util/is_nothrow_constructible/94003.cc: New test.
Clang 9 supports C++20 via -std=c++2a but doesn't support three-way
comparisons, so <stop_token> fails to compile. When the compiler doesn't
support default comparisons, this patch defines operator== and
operator!= for the _Stop_state_ref class. That is enough for the header
to be compiled with Clang. It allows operator== for stop_token and
stop_source to work, but not operator!= because that isn't explicitly
defined.
* include/std/stop_token (stop_token::_Stop_state_ref): Define
comparison operators explicitly if the compiler won't synthesize them.
This adds a tests that verifies taking the split_view of a non-forward range
works correctly. Doing so revealed a typo in one of _OuterIter's constructors.
It also revealed that the default constructor of
__gnu_test::test_range::iterator misbehaves, because by delegating to
Iter<T>(nullptr, nullptr) we perform a null-pointer deref at runtime in
input_iterator_wrapper's constructor due to the ITERATOR_VERIFY check therein.
Instead of delegating to this constructor it seems we can just inherit the
protected default constructor, which does not contain this ITERATOR_VERIFY
check.
libstdc++-v3/ChangeLog:
* include/std/ranges (split_view::_OuterIter::_OuterIter): Typo fix,
'address' -> 'std::__addressof'.
* testsuite/std/ranges/adaptors/split.cc: Test taking the split_view of
a non-forward input_range.
* testsuite/util/testsuite_iterators.h (output_iterator_wrapper): Make
default constructor protected instead of deleted, like with
input_iterator_wrapper.
(test_range::iterator): Add comment explaining that this type is used
only when the underlying wrapper is input_iterator_wrapper or
output_iterator_wrapper. Remove delegating defaulted constructor so
that the inherited default constructor is used instead.
... a call to ranges::begin on an input range.
This implements LWG 3286. The new wording for the single-argument constructor
for subrange is implemented by splitting the constructor into two delegating
constructors, one constrained by _S_store_size and the other by !_S_store_size.
Tested on x86_64-pc-linux-gnu, both added tests fail before the patch and pass
with the patch.
libstdc++-v3/ChangeLog:
LWG 3286 ranges::size is not required to be valid after a call to
ranges::begin on an input range
* include/std/ranges (subrange::subrange): Split single-argument
constructor into two, one constrained by _S_store_size and another by
!_S_store_size.
(take_view::begin): Call size() before calling ranges::begin(_M_base).
* testsuite/std/ranges/adaptors/lwg3286.cc: New test.
* testsuite/std/ranges/subrange/lwg3286.cc: New test.
These direct uses of _M_current should all be __current() so they are
valid when the base type doesn't satisfy the forward_range concept.
* include/std/ranges (split_view::_OuterIter::__at_end): Use __current
instead of _M_current.
(split_view::_OuterIter::operator++): Likewise.
Also introduce the _M_i_current() accessors to solve the problem of
access to the private member of _OuterIter from the iter_move and
iter_swap overloads (which are only friends of _InnerIter not
_OuterIter).
* include/std/ranges (transform_view::_Iterator::__iter_move): Remove.
(transform_view::_Iterator::operator*): Add noexcept-specifier.
(transform_view::_Iterator::iter_move): Inline __iter_move body here.
(split_view::_OuterIter::__current): Add noexcept.
(split_view::_InnerIter::__iter_swap): Remove.
(split_view::_InnerIter::__iter_move): Remove.
(split_view::_InnerIter::_M_i_current): New accessors.
(split_view::_InnerIter::__at_end): Use _M_i_current().
(split_view::_InnerIter::operator*): Likewise.
(split_view::_InnerIter::operator++): Likewise.
(iter_move(const _InnerIter&)): Likewise.
(iter_swap(const _InnerIter&, const _InnerIter&)): Likewise.
* testsuite/std/ranges/adaptors/split.cc: Check noexcept-specifier
for iter_move and iter_swap on split_view's inner iterator.
G++ fails to diagnose this non-dependent expression, but Clang doesn't
like it.
PR c++/94117
* include/std/ranges (ranges::transform_view::_Iterator::iter_move):
Change expression in noexcept-specifier to match function body.
The converting constructor of join_view::_Sentinel<true> needs to be able to
access the private members of join_view::_Sentinel<false>.
libstdc++-v3/ChangeLog:
* include/std/ranges (join_view::_Sentinel<_Const>): Befriend
join_view::_Sentinel<!_Const>.
* testsuite/std/ranges/adaptors/join.cc: Augment test.
When the target doesn't define PTHREAD_RWLOCK_INITIALIZER we use a
wrapper around pthread_wrlock_init, but the wrapper only takes one
argument and we try to call it with two.
This went unnnoticed on most targets because they do define the
PTHREAD_RWLOCK_INITIALIZER macro, but it causes a bootstrap failure on
darwin8.
PR libstdc++/93244
* include/std/shared_mutex [!PTHREAD_RWLOCK_INITIALIZER]
(__shared_mutex_pthread::__shared_mutex_pthread()): Remove incorrect
second argument to __glibcxx_rwlock_init.
* testsuite/30_threads/shared_timed_mutex/94069.cc: New test.
I don't think this is actually required to compile, because using
operator<< without a definition of the ostream doesn't seem valid to me.
But it's easy to make it work.
PR libstdc++/94051
* include/std/string_view: Include <bits/ostream_insert.h>.
* testsuite/21_strings/basic_string_view/inserters/94051.cc: New test.
The key property of this alias is not that it may be an empty type, but
that the type argument may not be used. The fact it's replaced by an
empty type is just an implementation detail. The name was also
backwards with respect to the bool argument.
This patch changes the name to better reflect its purpose.
* include/std/ranges (__detail::__maybe_empty_t): Rename to
__maybe_present_t.
(__adaptor::_RangeAdaptor, join_view, split_view): Use new name.
When the underlying range models common_range, then reverse_view::begin() is
already O(1) without caching. So we should disable the cache in this case too.
libstdc++-v3/ChangeLog:
* include/std/ranges (reverse_view::_S_needs_cached_begin): Set to false
whenever the underlying range models common_range.
This patch adds memoization to these four views so that their begin() has the
required amortized constant time complexity.
The cache is enabled only for forward_ranges and above because we need the
underlying iterator to be copyable and multi-pass in order for the cache to be
usable. In the general case we represent the cached result of begin() as a bare
iterator. This takes advantage of the fact that value-initialized forward
iterators can be compared to as per N3644, so we can use a value-initialized
iterator to denote the "empty" state of the cache.
As a special case, when the underlying range models random_access_range and when
it's profitable size-wise, then we cache the offset of the iterator from the
beginning of the range instead of caching the iterator itself.
Additionally, in drop_view and reverse_view we disable the cache when the
underlying range models random_access_range, because in these cases recomputing
begin() takes O(1) time anyway.
libstdc++-v3/ChangeLog:
* include/std/ranges (__detail::_CachedPosition): New struct.
(views::filter_view::_S_needs_cached_begin): New member variable.
(views::filter_view::_M_cached_begin): New member variable.
(views::filter_view::begin): Use _M_cached_begin to cache its
result.
(views::drop_view::_S_needs_cached_begin): New static member variable.
(views::drop_view::_M_cached_begin): New member variable.
(views::drop_view::begin): Use _M_cached_begin to cache its result
when _S_needs_cached_begin.
(views::drop_while_view::_M_cached_begin): New member variable.
(views::drop_while_view::begin): Use _M_cached_begin to cache its
result.
(views::reverse_view::_S_needs_cached_begin): New static member
variable.
(views::reverse_view::_M_cached_begin): New member variable.
(views::reverse_view::begin): Use _M_cached_begin to cache its result
when _S_needs_cached_begin.
* testsuite/std/ranges/adaptors/drop.cc: Augment test to check that
drop_view::begin caches its result.
* testsuite/std/ranges/adaptors/drop_while.cc: Augment test to check
that drop_while_view::begin caches its result.
* testsuite/std/ranges/adaptors/filter.cc: Augment test to check that
filter_view::begin caches its result.
* testsuite/std/ranges/adaptors/reverse.cc: Augment test to check that
reverse_view::begin caches its result.
Some of the range adaptors have distinct constant and non-constant
iterator/sentinel types, along with converting constructors that can convert a
non-constant iterator/sentinel to a constant iterator/sentinel. This patch adds
the missing appropriate friend declarations in order to make these converting
constructors well formed.
Strictly speaking it seems the friendship relations don't need to go both ways
-- we could get away with declaring e.g. friend _Iterator<false>; instead of
friend _Iterator<!_Const>; but both reference implementations seem to use the
latter symmetric form anyway.
libstdc++-v3/ChangeLog:
* include/std/ranges (transform_view::_Iterator<_Const>): Befriend
_Iterator<!_Const>.
(transform_view::_Sentinel<_Const>): Befriend _Sentinel<!_Const>.
(take_view::_Sentinel<_Const>): Likewise.
(take_while_view::_Sentinel<_Const>): Likewise.
(split_view::_OuterIter<_Const>): Befriend _OuterIter<!_Const>.
* testsuite/std/ranges/adaptors/split.cc: Augment test.
* testsuite/std/ranges/adaptors/take.cc: Augment test.
* testsuite/std/ranges/adaptors/take_while.cc: Augment test.
* testsuite/std/ranges/adaptors/transform.cc: Augment test.
We are calling _OuterIter::__current from _InnerIter::operator==, but the former
is private within this non-member friend. Fix this by calling
_OuterIter::operator== instead, which does the right thing here.
libstdc++-v3/ChangeLog:
PR libstdc++/93936
* include/std/ranges (split_view::_InnerIter::operator==): Compare
the operands' _M_i rather than their _M_i.current().
* testsuite/std/ranges/adaptors/split.cc: Augment test.
This introduces a couple of convenience alias templates to be used for
some repeated patterns using std::conditional_t.
* include/std/ranges (__detail::__maybe_empty_t): Define new helper
alias.
(__detail::__maybe_const_t): Likewise.
(__adaptor::_RangeAdaptor): Use __maybe_empty_t.
(transform_view, take_view, take_while_view, elements_view): Use
__maybe_const_t.
(join_view, split_view): Use both.
libstdc++-v3/ChangeLog:
LWG 3325 Constrain return type of transformation function for
transform_view
* include/std/ranges (transform_view): Constrain the return type of the
transformation function as per LWG 3325.
* testsuite/std/ranges/adaptors/lwg3325_neg.cc: New test.
libstdc++-v3/ChangeLog:
LWG 3292 iota_view is under-constrained
* include/std/ranges (iota_view): Require that _Winc models semiregular
as per LWG 3292.
* testsuite/std/ranges/iota/lwg3292_neg.cc: New test.
This fixes a dangling-reference issue with views::split and other multi-argument
adaptors that may take its extra arguments by reference.
When creating the _RangeAdaptorClosure in _RangeAdaptor::operator(), we
currently capture all provided arguments by value. When we then use the
_RangeAdaptorClosure and call it with a range, as in e.g.
v = views::split(p)(range),
we forward the range and the captures to the underlying adaptor routine. But
then when the temporary _RangeAdaptorClosure goes out of scope, the by-value
captures get destroyed and the references to these captures in the resulting view
become dangling.
This patch fixes this problem by capturing lvalue references by reference in
_RangeAdaptorClosure::operator(), and then forwarding the captures appropriately
to the underlying adaptor routine.
libstdc++-v3/ChangeLog:
* include/std/ranges (views::__adaptor::__maybe_refwrap): New utility
function.
(views::__adaptor::_RangeAdaptor::operator()): Add comments. Use
__maybe_refwrap to capture lvalue references by reference, and then use
unwrap_reference_t to forward the by-reference captures as references.
* testsuite/std/ranges/adaptors/split.cc: Augment test.
* testsuite/std/ranges/adaptors/split_neg.cc: New test.
We are forwarding the second argument of views::iota using the wrong type,
causing compile errors when calling views::iota with a value and bound of
different types, like in the test case below.
libstdc++-v3/ChangeLog:
* include/std/ranges (iota_view): Forward declare _Sentinel.
(iota_view::_Iterator): Befriend _Sentinel.
(iota_view::_Sentinel::_M_equal): New member function.
(iota_view::_Sentinel::operator==): Use it.
(views::_Iota::operator()): Forward __f using the correct type.
* testsuite/std/ranges/access/ssize.cc (test06): Don't call views::iota
with integers of different signedness, to appease iota_view's deduction
guide.
* testsuite/std/ranges/iota/iota_view.cc: Augment test.
Another piece of P1614R2 for C++20.
This also adds tests for operator< in C++11, which was present but
untested.
* include/std/system_error (error_category::operator<=>)
(operator<=>(const error_code&, const error_code&))
(operator<=>(const error_condition&, const error_condition&)): Define
for C++20.
* testsuite/19_diagnostics/error_category/operators/less.cc: New test.
* testsuite/19_diagnostics/error_category/operators/three_way.cc: New
test.
* testsuite/19_diagnostics/error_code/operators/equal.cc: Remove
incorrect comment.
* testsuite/19_diagnostics/error_code/operators/less.cc: New test.
* testsuite/19_diagnostics/error_code/operators/not_equal.cc: Remove
incorrect comment.
* testsuite/19_diagnostics/error_code/operators/three_way.cc: New test.
* testsuite/19_diagnostics/error_condition/operators/equal.cc: Remove
incorrect comment.
* testsuite/19_diagnostics/error_condition/operators/less.cc: New test.
* testsuite/19_diagnostics/error_condition/operators/not_equal.cc:
Remove incorrect comment.
* testsuite/19_diagnostics/error_condition/operators/three_way.cc: New
test.
* include/std/thread (thread:🆔:operator<=>): Define for C++20.
* testsuite/30_threads/thread/id/70294.cc: Do not take addresses of
functions in namespace std.
* testsuite/30_threads/thread/id/operators_c++20.cc: New test.
* include/std/concepts (__detail::__partially_ordered_with): Move here
from <compare>.
(totally_ordered, totally_ordered_with): Use __partially_ordered_with
to simplify definition (LWG 3331).
* libsupc++/compare (__detail::__partially_ordered_with): Move to
<concepts>.
* include/std/memory_resource (polymorphic_allocator::allocate)
(polymorphic_allocator::allocate_object): Change type of exception to
bad_array_new_length (LWG 3237).
* testsuite/20_util/polymorphic_allocator/lwg3237.cc: New test.
We already defined the traits in <type_traits> as now required by LWG
3348, but the macro was missing. This adds it.
* include/std/type_traits (__cpp_lib_unwrap_ref): Define (LWG 3348).
* include/std/version (__cpp_lib_unwrap_ref): Likewise.
* testsuite/20_util/unwrap_reference/1.cc: Check macro.
* testsuite/20_util/unwrap_reference/3.cc: New test.
* include/std/numeric (midpoint(T8, T*)): Do not check for complete
type during overload resolution, use static assert instead (LWG 3200).
* testsuite/26_numerics/midpoint/pointer.cc: Do not test with
incomplete type.
* testsuite/26_numerics/midpoint/pointer_neg.cc: New test.
The 23_containers/span/deduction.cc test was already passing, but only
because I had previously implemented the original proposed resolution of
3255. As pointed out in 3255 that original P/R was incorrect because it
broke construction from array xvalues. This reverts the incorrect part
of 3255 (and adds tests for the case it broke), and implements the
resolution of 3369 instead.
* include/std/span (span(T (&)[N])): Use non-deduced context to
prevent first parameter from interfering with class template argument
deduction (LWG 3369).
* testsuite/23_containers/span/deduction.cc: Add missing 'const'.
* testsuite/23_containers/span/lwg3255.cc: Check for construction from
rvalues.
* include/bits/range_access.h (range_size_t): Define alias template.
* include/std/ranges (all_view): Rename to views::all_t (LWG 3335).
* testsuite/std/ranges/adaptors/filter.cc: Adjust to new name.
Among other changes, P1983R0 resolves LWG 3278 in a different way, so this patch
also reverts the already-applied wording of LWG 3278.
The wording for US291 (the join_view::begin hunk) also required adding the
friend _Iterator<!_Const> to join_view::_Iterator. This friend is needed so
that _Iterator's converting constructor can access the private members of an
_Iterator of the opposite constness.
The wording for US283 has already been applied it seems.
libstdc++-v3/ChangeLog:
P1983R0 Wording for GB301, US296, US292, US291, and US283
* include/std/ranges (filter_view::pred): New member function.
(join_view::_Iterator::_Iterator): Remove now-redundant comment since
P1983R0 fixes the highlighted issue in the same way.
(join_view::_Iterator<_Const>): Add friend
join_view::_Iterator<!_Const>.
(join_view::_M_inner): Remove mutable specifier, effectively reverting
the proposed wording changes of P3278.
(join_view::begin): Refine the condition for when to return a const
iterator.
(split_view::_OuterIter::_OuterIter): Adjust constraints.
* testsuite/std/ranges/adaptors/filter.cc: Test that filter_view::pred
exists and works.
PR libstdc++/93818
* include/std/ranges (_RangeAdaptor): Add deduction guide.
(filter_view::_Iterator): Add alias _Vp_iter and use in place of
iterator_t<_Vp>.
(filter_view::_Iterator::_S_iter_cat()): Add 'typename'.
(transform_view::_Iterator): Add alias _Base_iter and use in place of
iterator_t<_Base>.
(transform_view::_Iterator::_S_iter_cat()): Add 'typename'.
(join_view::_Iterator): Add _Outer_iter and _Inner_iter aliases.
(join_view::_Iterator::_S_iter_cat()): Add 'typename'.
(split_view::_InnerIter::_S_iter_cat()): Likewise.
This includes fixes for first, last, as_bytes and as_writable_bytes
which were missing from the paper.
* include/std/span (__cpp_lib_span): Update value.
(span(It, size_type), span(It, End)): Make conditionally explicit. Add
assertion.
(span(R&&), span(const span<OType, OExtent>&)): Likewise and relax
constraints.
(span::first<Count>(), span::last<Count>()): Use explicit type in
return statement.
(as_bytes, as_writable_bytes): Likewise.
* include/std/version (__cpp_lib_span): Update value.
* testsuite/23_containers/span/1.cc: Check new value.
* testsuite/23_containers/span/2.cc: Check new value.
* testsuite/23_containers/span/explicit.cc: New test.
This makes the constraints consistent with the pre-Prague working paper.
* include/std/span (span::__is_compatible_array): Simplify alias
template by using requires-clause.
(span::__is_compatible_ref): New alias template for constraining
constructors.
(span::__is_compatible_iterator, span::__is_compatible_range): Remove.
(span(It, size_type), span(It, End)): Use __is_compatible_ref.
(span(T(&)[N], span(array<T, N>&), span(const array<T, N>&)): Remove
redundant parentheses.
(span(R&&)): Add missing constraints.
I find it easier to work with this class when the declarations match the
order in the C++2a working paper.
There's no need to use long, descriptive template parameter names like
_ContiguousIterator when the parameter is already constrained by the
std::contiguous_iterator concept. This is also consistent with the
naming conventions in the working paper.
* include/std/span (span): Reorder members and rename template
parameters to match declarations in the C++2a working paper.
Following this change it's no longer possible to use std::span with
structured bindings or with the tuple-like API. It will probably come
back for C++23 though.
P2116R0 Remove tuple-like protocol support from fixed-extent span
* include/std/span (get, tuple_size, tuple_element): Remove.
* testsuite/23_containers/span/everything.cc: Remove checks for
tuple-like API.
* testsuite/23_containers/span/get_neg.cc: Remove.
* testsuite/23_containers/span/tuple_element_dynamic_neg.cc: Remove.
* testsuite/23_containers/span/tuple_element_oob_neg.cc: Remove.
* testsuite/23_containers/span/tuple_size_neg.cc: Remove.
This removes the complicated std::boolean concept, as agreed in Prague.
* include/bits/ranges_algo.h (__find_fn, __find_first_of_fn)
(__adjacent_find_fn): Cast result of predicate to bool.
* include/std/concepts (__boolean): Remove.
(__detail::__boolean_testable_impl, __detail::__boolean_testable): Add
new helper concepts.
(__detail::__weakly_eq_cmp_with, totally_ordered, totally_ordered_with)
(predicate): Use __boolean_testable instead of boolean.
* libsupc++/compare (__detail::__partially_ordered, _Synth3way):
Likewise.
