This paper has been included in the C++20 draft, but the changes to add
noexcept can be made unconditionally, to apply for C++11 too.
* include/std/chrono (duration_values::zero(), duration_values::min())
(duration_values::max()): Add noexcept.
(duration::zero(), duration::min(), duration::max()): Likewise.
(time_point::zero(), time_point::min(), time_point::max()): Likewise.
* testsuite/20_util/duration/requirements/noexcept.cc: New test.
* testsuite/20_util/time_point/requirements/noexcept.cc: New test.
From-SVN: r267865
The C++2a draft specifies the value 201811L for this, but as an
extension we return the number of elements erased. This is expected to
be standardised, so the macro has the value 201900L until a proper value
is specified in the draft.
* include/bits/erase_if.h: Define __cpp_lib_erase_if.
* include/std/deque: Likewise.
* include/std/forward_list: Likewise.
* include/std/list: Likewise.
* include/std/string: Likewise.
* include/std/vector: Likewise.
* include/std/version: Likewise.
* testsuite/21_strings/basic_string/erasure.cc: Test macro.
* testsuite/23_containers/deque/erasure.cc: Likewise.
* testsuite/23_containers/forward_list/erasure.cc: Likewise.
* testsuite/23_containers/list/erasure.cc: Likewise.
* testsuite/23_containers/map/erasure.cc: Likewise.
* testsuite/23_containers/set/erasure.cc: Likewise.
* testsuite/23_containers/unordered_map/erasure.cc: Likewise.
* testsuite/23_containers/unordered_set/erasure.cc: Likewise.
* testsuite/23_containers/vector/erasure.cc: Likewise.
From-SVN: r267810
2019-01-10 Ville Voutilainen <ville.voutilainen@gmail.com>
Jonathan Wakely <jwakely@redhat.com>
Implement LWG 2221
* config/abi/pre/gnu.ver (GLIBCXX_3.4): Tighten patterns.
(GLIBCXX_3.4.26): Add new exports.
* include/Makefile.am: Add ostream-inst.cc. Move string-inst.cc to
correct list of sources.
* include/Makefile.in: Regenerate.
* include/std/ostream (operator<<(nullptr_t)): New member function.
* src/c++17/ostream-inst.cc: New file.
* testsuite/27_io/basic_ostream/inserters_other/char/lwg2221.cc: New
test.
Co-Authored-By: Jonathan Wakely <jwakely@redhat.com>
From-SVN: r267808
Hoist the duplicated code from the _Optional_payload partial
specializations into the _Optional_payload_base base class.
* include/std/optional (_Optional_payload_base::_M_copy_assign): New
member function to perform non-trivial assignment.
(_Optional_payload_base::_M_move_assign): Likewise.
(_Optional_payload<T, true, false, true>::operator=)
(_Optional_payload<T, true, true, false>::operator=)
(_Optional_payload<T, true, false, false>::operator=): Call
_M_copy_assign and/or _M_move_assign to do non-trivial assignments.
From-SVN: r267761
When the contained value is not trivially copy (or move) constructible
the union's copy (or move) constructor will be deleted, and so the
_Optional_payload delegating constructors are invalid. G++ fails to
diagnose this because it incorrectly performs copy elision in the
delegating constructors. Clang does diagnose it (llvm.org/PR40245).
The solution is to avoid performing any copy (or move) when the
contained value's copy (or move) constructor isn't trivial. Instead the
contained value can be constructed by calling _M_construct. This is OK,
because the relevant constructor doesn't need to be constexpr when the
contained value isn't trivially copy (or move) constructible.
Additionally, this patch removes a lot of code duplication in the
_Optional_payload partial specializations and the _Optional_base partial
specialization, by hoisting it into common base classes.
The Python pretty printer for std::optional needs to be adjusted to
support the new layout. Retain support for the old layout, and add a
test to verify that the support still works.
PR libstdc++/87855
* include/std/optional (_Optional_payload_base): New class template
for common code hoisted from _Optional_payload specializations. Use
a template for the union, to allow a partial specialization for
types with non-trivial destructors. Add constructors for in-place
initialization to the union.
(_Optional_payload(bool, const _Optional_payload&)): Use _M_construct
to perform non-trivial copy construction, instead of relying on
non-standard copy elision in a delegating constructor.
(_Optional_payload(bool, _Optional_payload&&)): Likewise for
non-trivial move construction.
(_Optional_payload): Derive from _Optional_payload_base and use it
for everything except the non-trivial assignment operators, which are
defined as needed.
(_Optional_payload<false, C, M>): Derive from the specialization
_Optional_payload<true, false, false> and add a destructor.
(_Optional_base_impl::_M_destruct, _Optional_base_impl::_M_reset):
Forward to corresponding members of _Optional_payload.
(_Optional_base_impl::_M_is_engaged, _Optional_base_impl::_M_get):
Hoist common members from _Optional_base.
(_Optional_base): Make all members and base class public.
(_Optional_base::_M_get, _Optional_base::_M_is_engaged): Move to
_Optional_base_impl.
* python/libstdcxx/v6/printers.py (StdExpOptionalPrinter): Add
support for new std::optional layout.
* testsuite/libstdc++-prettyprinters/compat.cc: New test.
From-SVN: r267742
The previous patch for PR 87431 assumed that initialing a scalar type
could not throw, but it can obtain its value via a conversion operator,
which could throw. This meant the variant could get into a valueless
state, but the valueless_by_exception() member function would always
return false.
This patch fixes it by changing the emplace members to have strong
exception safety when initializing a contained value of trivially
copyable type. The _M_valid() member gets a corresponding change to
always return true for trivially copyable types, not just scalar types.
Strong exception safety (i.e. never becoming valueless) is achieved by
only replacing the current contained value once any potentially throwing
operations have completed. If constructing the new contained value can
throw then a new std::variant object is constructed to hold it, and then
move-assigned to *this (which won't throw).
PR libstdc++/87431
* include/std/variant (_Variant_storage<true, _Types...>::_M_valid):
Check is_trivially_copyable instead of is_scalar.
(variant::emplace<N, Args>(Args&&...)): If construction of the new
contained value can throw and its type is trivially copyable then
construct into a temporary variant and move from it, to provide the
strong exception safety guarantee.
(variant::emplace<N, U, Args>(initializer_list<U>, Args&&...)):
Likewise.
* testsuite/20_util/variant/87431.cc: New test.
* testsuite/20_util/variant/run.cc: Adjust test so that throwing
conversion causes valueless state.
From-SVN: r267614
* include/std/string_view [__cplusplus > 201703L]
(basic_string_view::starts_with(basic_string_view)): Implement
proposed resolution of LWG 3040 to avoid redundant length check.
(basic_string_view::starts_with(_CharT)): Implement proposed
resolution of LWG 3040 to check at most one character.
(basic_string_view::ends_with(_CharT)): Likewise.
From-SVN: r267234
2018-11-29 Edward Smith-Rowland <3dw4rd@verizon.net>
Only include bits/stl_algo.h for C++20.
* include/std/deque: Only include bits/stl_algo.h for C++20.
* include/std/string: Ditto.
* include/std/vector: Ditto.
From-SVN: r266624
Now that __alignof__ and alignof sometimes disagree it matters which one
we use. The standard says that std::alignment_of<T>::value equals
alignof(T), so we need to use that.
Change the only uses of alignment_of to use __alignof__ to avoid a
change in alignment.
PR libstdc++/88119
* include/ext/aligned_buffer.h (__aligned_membuf): Add comment.
(__aligned_buffer): Use __alignof__ instead of std::alignment_of.
* include/std/type_traits (alignment_of): Use alignof instead of
__alignof__.
* testsuite/20_util/alignment_of/value.cc: Fix test to check values
match alignof not __alignof__, as required by the standard.
From-SVN: r266613
PR libstdc++/88111
* include/std/memory_resource (pool_options): Add Doxygen comments.
* src/c++17/memory_resource.cc (pool_sizes): Only use suitable values
on targets with 16-bit or 20-bit size_t type.
(munge_options): Make default values depend on width of size_t type.
From-SVN: r266353
PR libstdc++/87855
Also implement P0602R4 (variant and optional
should propagate copy/move triviality) for std::optional.
* include/std/optional (_Optional_payload): Change
the main constraints to check constructibility in
addition to assignability.
(operator=): Make constexpr.
(_M_reset): Likewise.
(_M_construct): Likewise.
(operator->): Likewise.
* testsuite/20_util/optional/assignment/8.cc: Adjust.
* testsuite/20_util/optional/assignment/9.cc: New.
From-SVN: r266278
* include/std/string_view (basic_string_view::copy): Use traits to
copy.
* testsuite/21_strings/basic_string_view/operations/copy/char/2.cc:
New test.
* testsuite/21_strings/basic_string_view/operations/copy/wchar_t/2.cc:
New test.
From-SVN: r266269
Define the thread-safe pool resource, using a shared_mutex to allow
multiple threads to concurrently allocate from thread-specific pools.
Define new weak symbols for the pthread_rwlock_t functions, to avoid
making libstdc++.so depend on libpthread.so
When the necessary Gthread support is absent only define the
feature-test macro to 1, rather than 201603. This is intended to imply
incomplete support, because everything except synchronized_pool_resource
works.
Implement std::pmr::synchronized_pool_resource
* config/abi/pre/gnu.ver: Add new symbols.
* include/std/memory_resource [_GLIBCXX_HAS_GTHREADS]
(__cpp_lib_memory_resource): Define to expected value, 201603.
(synchronized_pool_resource): New class.
[!_GLIBCXX_HAS_GTHREADS] (__cpp_lib_memory_resource): Define to 1.
* include/std/shared_mutex (__glibcxx_rwlock_rdlock)
(__glibcxx_rwlock_tryrdlock, __glibcxx_rwlock_wrlock)
(__glibcxx_rwlock_trywrlock, __glibcxx_rwlock_unlock)
(__glibcxx_rwlock_destroy, __glibcxx_rwlock_init)
(__glibcxx_rwlock_timedrdlock, __glibcxx_rwlock_timedwrlock): Define
weak symbols for POSIX rwlock functions.
(__shared_mutex_pthread): Use weak symbols.
* include/std/version (__cpp_lib_memory_resource): Define.
* src/c++17/memory_resource.cc [_GLIBCXX_HAS_GTHREADS]
(synchronized_pool_resource::_TPools): New class.
(destroy_TPools): New function for pthread_key_create destructor.
(synchronized_pool_resource::synchronized_pool_resource)
(synchronized_pool_resource::~synchronized_pool_resource)
(synchronized_pool_resource::release)
(synchronized_pool_resource::do_allocate)
(synchronized_pool_resource::do_deallocate): Define public members.
(synchronized_pool_resource::_M_thread_specific_pools)
(synchronized_pool_resource::_M_alloc_tpools)
(synchronized_pool_resource::_M_alloc_shared_tpools): Define private
members.
* testsuite/20_util/synchronized_pool_resource/allocate.cc: New test.
* testsuite/20_util/synchronized_pool_resource/cons.cc: New test.
* testsuite/20_util/synchronized_pool_resource/is_equal.cc: New test.
* testsuite/20_util/synchronized_pool_resource/multithreaded.cc: New
test.
* testsuite/20_util/synchronized_pool_resource/release.cc: New test.
* testsuite/performance/20_util/memory_resource/pools.cc: Add
multithreaded tests using pmr::synchronized_pool_resource.
From-SVN: r266242
Implement P0318R1 unwrap_ref_decay and unwrap_reference
* include/std/type_traits (unwrap_reference, unwrap_reference_t)
(unwrap_ref_decay, unwrap_ref_decay_t): New traits and aliases.
* testsuite/20_util/unwrap_reference/1.cc: New test.
* testsuite/20_util/unwrap_reference/2.cc: New test.
From-SVN: r266010
PR libstdc++/87538
* include/std/functional (_Not_fn::operator()): Check value of
__is_nothrow_invocable as well.
* testsuite/20_util/function_objects/not_fn/87538.cc: New test.
From-SVN: r264921
Calling std::get will check some static assertions and also do a runtime
check for a valid index before calling __detail::__variant::__get. The
std::visit function already handles the case where any variant has an
invalid index, so __get can be used directly in __visit_invoke.
* include/std/variant (__gen_vtable_impl::__visit_invoke): Call __get
directly instead of get, as caller ensures correct index is used.
(holds_alternative, get, get_if): Remove redundant inline specifiers.
(_VARIANT_RELATION_FUNCTION_TEMPLATE): Likewise.
From-SVN: r264786
In r263225 (d2e378182a), I fixed
condition_variable::wait_for to use std::chrono::steady_clock for the wait.
Unfortunately, I failed to spot that the same fix is required for the
wait_for variant that takes a predicate too.
2018-09-25 Mike Crowe <mac@mcrowe.com>
* include/std/condition_variable (condition_variable::wait_for): Use
steady clock in overload that uses a predicate.
From-SVN: r264575
If a std::variant can never get into valueless state then we don't need
to do a runtime check for a valid alternative.
PR libstdc++/87431
* include/std/variant (_Variant_storage<true, _Types...>::_M_valid):
Avoid runtime test when all alternatives are scalars and so cannot
throw during initialization.
From-SVN: r264574
The bug https://bugs.llvm.org/show_bug.cgi?id=33222 is now fixed on
Clang trunk, so the workaround won't be needed for Clang 8.0 and later.
* include/std/variant (variant) [__clang__]: Limit workaround to
Clang 7 and older.
From-SVN: r264271
For values where the result cannot be represented the shift width would
be equal to the width of the type, which is undefined. Perform two
well-defined shifts instead of one possible undefined shift.
* include/bits/hashtable_policy.h (__clp2): Fix calculation for LLP64
targets where sizeof(size_t) > sizeof(long). Avoid undefined shifts
of the number of bits in the type.
* include/std/bit (__ceil2): Avoid undefined shifts.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Test values with
the most signifiant bit set.
From-SVN: r263986
The _Tuple_impl base class can be used to disable copy/move assignment,
without requiring an extra base class.
Exception specifications on std::tuple assignment and swap functions can
be defined directly using is_nothrow_swappable, instead of querying the
base classes.
PR libstdc++/86963
* include/std/tuple (_Tuple_impl::operator=): Define as deleted.
(_Tuple_impl::_M_assign): New functions to perform assignment instead
of assignment operators.
(_Tuple_impl::_M_swap): Remove exception specification.
(_Tuple_impl<_Idx, _Head>): Likewise.
(_TC::_NonNestedTuple, _TC::_NotSameTuple): Use __remove_cvref_t.
(__tuple_base): Remove.
(tuple, tuple<_T1, _T2>): Remove inheritance from __tuple_base.
(tuple::operator=, tuple<_T1, _T2>::operator=): Call _M_assign.
(tuple::swap, tuple<_T1, _T2>::swap): Define exception specification
using __is_nothrow_swappable.
(tuple<_T1, _T2>::tuple(_U1&&, _U2&&)): Use __remove_cvref_t.
From-SVN: r263661
* include/std/optional (_Optional_payload): Use variable templates
for conditions in default template arguments and exception
specifications.
(optional): Likewise. Adjust indentation.
(optional::__not_self, optional::__not_tag, optional::_Requires): New
SFINAE helpers.
(optional::optional): Use new helpers in constructor constraints.
* include/std/type_traits (__or_v, __and_v): New variable templates.
* testsuite/20_util/optional/cons/value_neg.cc: Change dg-error to
dg-prune-output. Remove unused header.
From-SVN: r263657
PR libstdc++/86963
* include/std/tuple (__tuple_base): New class template with deleted
copy assignment operator.
(tuple, tuple<_T1, _T2>): Derive from __tuple_base<tuple> so that
implicit copy/move assignment operator will be deleted/suppressed.
(tuple::__assignable, tuple<_T1, _T2>::__assignable): New helper
functions for SFINAE constraints on assignment operators.
(tuple::__nothrow_assignable, tuple<_T1, _T2>::__nothrow_assignable):
New helper functions for exception specifications.
(tuple::operator=(const tuple&), tuple::operator=(tuple&&))
(tuple<_T1, _T2>::operator=(const tuple&))
(tuple<_T1, _T2>::operator=(tuple&&)): Change parameter types to
__nonesuch_no_braces when the operator should be defined implicitly.
Use __nothrow_assignable for exception specifications.
(tuple::operator=(const tuple<_UElements...>&))
(tuple::operator=(tuple<_UElements...>&&))
(tuple<_T1, _T2>::operator=(const tuple<_U1, _U2>&))
(tuple<_T1, _T2>::operator=(tuple<_U1, _U2>&&))
(tuple<_T1, _T2>::operator=(const pair<_U1, _U2>&))
(tuple<_T1, _T2>::operator=(pair<_U1, _U2>&&)): Constrain using
__assignable and use __nothrow_assignable for exception
specifications.
* python/libstdcxx/v6/printers.py (is_specialization_of): Accept
gdb.Type as first argument, instead of a string.
(StdTuplePrinter._iterator._is_nonempty_tuple): New method to check
tuple for expected structure.
(StdTuplePrinter._iterator.__init__): Use _is_nonempty_tuple.
* testsuite/20_util/tuple/dr2729.cc: New test.
* testsuite/20_util/tuple/element_access/get_neg.cc: Change dg-error
to dg-prune-output.
From-SVN: r263625
C++17 says to use std::uncaught_exceptions() here instead of
std::uncaught_exception() but since we only care whether the result is
non-zero (and we aren't planning to remove the deprecated version) we
can just keep using std::uncaught_exception() and suppress the warning.
* include/std/ostream (basic_ostream::sentry::~sentry): Suppress
deprecation warnings for using uncaught_exception().
From-SVN: r263593
Remove duplicated logic in experimental::pmr::polymorphic_allocator by
calling the __uses_allocator_construct helper.
Fix bugs in std::pmr::polymorphic_allocator with incorrect SFINAE
constraint and incorrect argument order.
* include/bits/uses_allocator.h (__uses_allocator_construct): Qualify
calls to __uses_allocator_construct_impl and __use_alloc.
* include/experimental/memory_resource
(polymorphic_allocator::_M_construct): Remove.
(polymorphic_allocator::construct): Call __uses_allocator_construct.
Qualify calls to __use_alloc.
* include/std/memory_resource (polymorphic_allocator::construct): Fix
type in SFINAE constraint. Use constexpr if instead of tag dispatching
to _S_construct overloads.
(polymorphic_allocator::construct(pair<T1, T2>*, ...)): Fix order of
arguments to _S_construct_p.
(polymorphic_allocator::_S_construct): Remove.
(polymorphic_allocator::_S_construct_p): Return allocators by value
not by reference.
* include/std/scoped_allocator (scoped_allocator_adaptor::construct):
Qualify calls to __use_alloc.
* testsuite/20_util/polymorphic_allocator/construct_pair.cc: New test,
copied from testsuite/20_util/scoped_allocator/construct_pair.cc.
* testsuite/experimental/polymorphic_allocator/1.cc: New test.
* testsuite/experimental/polymorphic_allocator/construct_pair.cc:
New test.
From-SVN: r263566
These aliases are placed in the top-level header, e.g. <vector> not
<bits/stl_vector.h>. This ensures that they refer to whichever of
std::vector or __debug::vector or __profile::vector is in use when the
header is included.
* include/std/deque (std::pmr::deque): Declare alias.
* include/std/forward_list (std::pmr::forward_list): Likewise.
* include/std/list (std::pmr::list): Likewise.
* include/std/map (std::pmr::map, std::pmr::multimap): Likewise.
* include/std/regex (std::pmr::match_results, std::pmr::cmatch)
(std::pmr::smatch, std::pmr::wcmatch, std::pmr::wsmatch): Likewise.
* include/std/set (std::pmr::set, std::pmr::multiset): Likewise.
* include/std/string (std::pmr::basic_string, std::pmr::string)
(std::pmr::u16string, std::pmr::u32string, std::pmr::wstring):
Likewise.
* include/std/unordered_map (std::pmr::unordered_map)
(std::pmr::unordered_multimap): Likewise.
* include/std/unordered_set (std::pmr::unordered_set)
(std::pmr::unordered_multiset): Likewise.
* include/std/vector (std::pmr::vector): Likewise.
* testsuite/21_strings/basic_string/types/pmr_typedefs.cc: New test.
* testsuite/23_containers/deque/types/pmr_typedefs.cc: New test.
* testsuite/23_containers/forward_list/pmr_typedefs.cc: New test.
* testsuite/23_containers/list/pmr_typedefs.cc: New test.
* testsuite/23_containers/map/pmr_typedefs.cc: New test.
* testsuite/23_containers/multimap/pmr_typedefs.cc: New test.
* testsuite/23_containers/multiset/pmr_typedefs.cc: New test.
* testsuite/23_containers/set/pmr_typedefs.cc: New test.
* testsuite/23_containers/unordered_map/pmr_typedefs.cc: New test.
* testsuite/23_containers/unordered_multimap/pmr_typedefs.cc: New
test.
* testsuite/23_containers/unordered_multiset/pmr_typedefs.cc: New
test.
* testsuite/23_containers/unordered_set/pmr_typedefs.cc: New test.
* testsuite/23_containers/vector/pmr_typedefs.cc: New test.
* testsuite/28_regex/match_results/pmr_typedefs.cc: New test.
From-SVN: r263456
PR libstdc++/86874
* include/std/variant (_Copy_ctor_base::_M_destructive_move): Define
here instead of in _Move_assign_base.
(_Copy_ctor_base<true, _Types...>::_M_destructive_move): Define.
(_Copy_assign_base::operator=): Use _M_destructive_move when changing
the contained value to another alternative.
(_Move_assign_base::operator=): Likewise.
(_Move_assign_base::_M_destructive_move): Remove.
* testsuite/20_util/variant/86874.cc: New test.
From-SVN: r263365
Jonathan Wakely