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.
__dp_sign precision indicates that we found out what iterator comes first or
last in the range. __dp_sign_max_size is the same plus it gives the information
of the max size of the range that is to say the max_size value such that
distance(lhs, rhs) < max_size.
Thanks to this additional information we are able to tell when a copy of n elements
to that range will fail even if we do not know exactly how large it is.
This patch makes sure that we are properly using this information.
libstdc++-v3/ChangeLog:
PR libstdc++/99402
* include/debug/helper_functions.h (__can_advance(_InputIterator,
const std::pair<_Diff, _Distance_precision>&, int)): New.
(__can_advance(const _Safe_iterator<>&,
const std::pair<_Diff, _Distance_precision>&, int)): New.
* include/debug/macros.h (__glibcxx_check_can_increment_dist): New,
use latter.
(__glibcxx_check_can_increment_range): Adapt to use latter.
(__glibcxx_check_can_decrement_range): Likewise.
* include/debug/safe_iterator.h
(_Safe_iterator<>::_M_can_advance(const std::pair<_Diff, _Distance_precision>&,
int)): New.
(__can_advance(const _Safe_iterator<>&,
const std::pair<_Diff, _Distance_precision>&, int)): New.
* include/debug/safe_iterator.tcc
(_Safe_iterator<>::_M_can_advance(const std::pair<_Diff, _Distance_precision>&,
int)): New.
(_Safe_iterator<>::_M_valid_range(const _Safe_iterator<>&,
std::pair<difference_type, _Distance_precision>&, bool)): Adapt for
__dp_sign_max_size.
(__copy_move_a): Adapt to use __glibcxx_check_can_increment_dist.
(__copy_move_backward_a): Likewise.
(__equal_aux): Likewise.
* include/debug/stl_iterator.h (__can_advance(const std::reverse_iterator<>&,
const std::pair<_Diff, _Distance_precision>&, int)): New.
(__can_advance(const std::move_iterator<>&,
const std::pair<_Diff, _Distance_precision>&, int)): New.
* testsuite/25_algorithms/copy/debug/99402.cc: New test.
This adds missing includes to internal library headers which get
included from more than one other header, so that they can be compiled
as a stand-alone header unit.
For existing use cases these includes are no-ops because they're already
done by the header that includes these files. For compiling them as a
header unit, this ensures that they include what they use.
libstdc++-v3/ChangeLog:
PR libstdc++/99413
* include/bits/align.h: Include debug/assertions.h.
* include/bits/codecvt.h: Include bits/c++config.h.
* include/bits/enable_special_members.h: Likewise.
* include/bits/erase_if.h: Likewise.
* include/bits/functional_hash.h: Include <type_traits>.
* include/bits/invoke.h: Include bits/move.h.
* include/bits/ostream_insert.h: Include bits/exception_defines.h.
* include/bits/parse_numbers.h: Include <type_traits>.
* include/bits/predefined_ops.h: Include bits/c++config.h.
* include/bits/range_access.h: Include bits/stl_iterator.h.
* include/bits/stl_bvector.h: Do not include bits/stl_vector.h.
* include/bits/stl_iterator.h: Include bits/stl_iterator_base_types.h.
* include/bits/stl_uninitialized.h: Include bits/stl_algobase.h.
* include/bits/uniform_int_dist.h: Include bits/concept_check.h.
* include/bits/unique_lock.h: Include bits/std_mutex.h.
* include/debug/assertions.h: Include bits/c++config.h.
Add unordered containers heterogeneous lookup member functions find, count, contains and
equal_range in C++20. Those members are considered for overload resolution only if hash and
equal functors used to instantiate the container have a nested is_transparent type.
libstdc++-v3/ChangeLog:
* include/bits/stl_tree.h
(__has_is_transparent, __has_is_transparent_t): Move...
* include/bits/stl_function.h: ...here.
* include/bits/hashtable_policy.h (_Hash_code_base<>::_M_hash_code_tr): New..
(_Hashtable_base<>::_M_equals_tr): New.
* include/bits/hashtable.h (_Hashtable<>::_M_find_tr, _Hashtable<>::_M_count_tr,
_Hashtable<>::_M_equal_range_tr): New member function templates to perform
heterogeneous lookup.
(_Hashtable<>::_M_find_before_node_tr): New.
(_Hashtable<>::_M_find_node_tr): New.
* include/bits/unordered_map.h (unordered_map::find<>, unordered_map::count<>,
unordered_map::contains<>, unordered_map::equal_range<>): New member function
templates to perform heterogeneous lookup.
(unordered_multimap::find<>, unordered_multimap::count<>,
unordered_multimap::contains<>, unordered_multimap::equal_range<>): Likewise.
* include/bits/unordered_set.h (unordered_set::find<>, unordered_set::count<>,
unordered_set::contains<>, unordered_set::equal_range<>): Likewise.
(unordered_multiset::find<>, unordered_multiset::count<>,
unordered_multiset::contains<>, unordered_multiset::equal_range<>): Likewise.
* include/debug/unordered_map
(unordered_map::find<>, unordered_map::equal_range<>): Likewise.
(unordered_multimap::find<>, unordered_multimap::equal_range<>): Likewise.
* include/debug/unordered_set
(unordered_set::find<>, unordered_set::equal_range<>): Likewise.
(unordered_multiset::find<>, unordered_multiset::equal_range<>): Likewise.
* testsuite/23_containers/unordered_map/operations/1.cc: New test.
* testsuite/23_containers/unordered_multimap/operations/1.cc: New test.
* testsuite/23_containers/unordered_multiset/operations/1.cc: New test.
* testsuite/23_containers/unordered_set/operations/1.cc: New test.
The __glibcxx_check_can_[increment|decrement]_range macros are using the
_GLIBCXX_DEBUG_VERIFY_COND_AT macro which is not constexpr compliant and will produce nasty
diagnostics rather than the std::__failed_assertion dedicated to constexpr. Replace it with
correct _GLIBCXX_DEBUG_VERIFY_AT_F.
libstdc++-v3/ChangeLog:
* include/debug/macros.h (__glibcxx_check_can_increment_range): Replace
_GLIBCXX_DEBUG_VERIFY_COND_AT usage with _GLIBCXX_DEBUG_VERIFY_AT_F.
(__glibcxx_check_can_decrement_range): Likewise.
* testsuite/25_algorithms/copy_backward/constexpr.cc (test03): New.
* testsuite/25_algorithms/copy/debug/constexpr_neg.cc: New test.
* testsuite/25_algorithms/copy_backward/debug/constexpr_neg.cc: New test.
* testsuite/25_algorithms/equal/constexpr_neg.cc: New test.
* testsuite/25_algorithms/equal/debug/constexpr_neg.cc: New test.
libstdc++-v3/ChangeLog:
* include/debug/assertions.h (__glibcxx_requires_non_empty_range):
Remove __builtin_expect.
(__glibcxx_requires_subscript): Likewise.
(__glibcxx_requires_nonempty): Likewise.
* include/debug/formatter.h (__check_singular): Add C++11 constexpr
qualification.
* include/debug/helper_functions.h (__check_singular): Likewise. Skip
check if constant evaluated.
(__valid_range): Do not skip check if constant evaluated.
* include/debug/macros.h (_GLIBCXX_DEBUG_VERIFY_COND_AT): Add
__builtin_expect.
(_GLIBCXX_DEBUG_VERIFY_AT_F): Use __glibcxx_assert_1.
* testsuite/21_strings/basic_string_view/element_access/char/back_constexpr_neg.cc:
New test.
* testsuite/21_strings/basic_string_view/element_access/char/constexpr.cc: New test.
* testsuite/21_strings/basic_string_view/element_access/char/constexpr_neg.cc: New test.
* testsuite/21_strings/basic_string_view/element_access/char/front_back_constexpr.cc:
New test.
* testsuite/21_strings/basic_string_view/element_access/char/front_constexpr_neg.cc:
New test.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/back_constexpr_neg.cc:
New test.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr.cc: New test.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr_neg.cc: New test.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/front_constexpr_neg.cc:
New test.
* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_neg.cc: New test.
* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_pred_neg.cc: New test.
* testsuite/25_algorithms/lower_bound/debug/constexpr_valid_range_neg.cc: New test.
* testsuite/25_algorithms/lower_bound/debug/partitioned_neg.cc: New test.
* testsuite/25_algorithms/lower_bound/debug/partitioned_pred_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_pred_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/constexpr_valid_range_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/partitioned_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/partitioned_pred_neg.cc: New test.
The name __deref is defined as a macro by Windows headers.
This renames the __deref() helper function to __ref. It doesn't actually
dereference an iterator. it just has the same type as the iterator's
reference type.
libstdc++-v3/ChangeLog:
PR libstdc++/97362
* doc/html/manual/source_code_style.html: Regenerate.
* doc/xml/manual/appendix_contributing.xml: Add __deref to
BADNAMES.
* include/debug/functions.h (_Irreflexive_checker::__deref):
Rename to __ref.
* testsuite/17_intro/badnames.cc: Check __deref.
The C++ LWG recently confirmed that self-move assignment should not have
undefined behaviour for standard containers (see the proposed resolution
of LWG 2839). The result should be a valid but unspecified value, just
like other times when a container is moved from.
Our std::list, std::__cxx11::basic_string and unordered containers all
have bugs which result in undefined behaviour.
For std::list the problem is that we clear the previous contents using
_M_clear() instead of clear(). This means the _M_next, _M_prev and
_M_size members are not zeroed, and so after we "update" them (with
their existing values), we are left with dangling pointers and a
non-zero size, but no elements.
For the unordered containers the problem is similar. _Hashtable first
deallocates the existing contents, then takes ownership of the pointers
from the RHS object (which has just had its contents deallocated so the
pointers are dangling).
For std::basic_string it's a little more subtle. When the string is
local (i.e. fits in the SSO buffer) we use char_traits::copy to copy the
contents from this->data() to __rhs.data(). When &__rhs == this that
copy violates the precondition that the ranges don't overlap. We only
need to check for self-move for this case where it's local, because the
only other case that can be true for self-move is that it's non-local
but the allocators compare equal. In that case the data pointer is
neither deallocated nor leaked, so the result is well-defined.
This patch also makes a small optimization for std::deque move
assignment, to use the efficient move when is_always_equal is false, but
the allocators compare equal at runtime.
Finally, we need to remove all the Debug Mode checks which abort the
program when a self-move is detected, because it's not undefined to do
that.
Before PR 85828 can be closed we should also look into fixing
std::shuffle so it doesn't do any redundant self-swaps.
libstdc++-v3/ChangeLog:
PR libstdc++/85828
* include/bits/basic_string.h (operator=(basic_string&&)): Check
for self-move before copying with char_traits::copy.
* include/bits/hashtable.h (operator=(_Hashtable&&)): Check for
self-move.
* include/bits/stl_deque.h (_M_move_assign1(deque&&, false_type)):
Check for equal allocators.
* include/bits/stl_list.h (_M_move_assign(list&&, true_type)):
Call clear() instead of _M_clear().
* include/debug/formatter.h (__msg_self_move_assign): Change
comment.
* include/debug/macros.h (__glibcxx_check_self_move_assign):
(_GLIBCXX_DEBUG_VERIFY): Remove.
* include/debug/safe_container.h (operator=(_Safe_container&&)):
Remove assertion check for safe move and make it well-defined.
* include/debug/safe_iterator.h (operator=(_Safe_iterator&&)):
Remove assertion check for self-move.
* include/debug/safe_local_iterator.h
(operator=(_Safe_local_iterator&&)): Likewise.
* testsuite/21_strings/basic_string/cons/char/self_move.cc: New test.
* testsuite/23_containers/deque/cons/self_move.cc: New test.
* testsuite/23_containers/forward_list/cons/self_move.cc: New test.
* testsuite/23_containers/list/cons/self_move.cc: New test.
* testsuite/23_containers/set/cons/self_move.cc: New test.
* testsuite/23_containers/unordered_set/cons/self_move.cc: New test.
* testsuite/23_containers/vector/cons/self_move.cc: New test.
Respect DR 526 in implementation of std::[forward_]list remove/remove_if/unique.
[forward_]list::remove was already implementing it but the implementation has
been modified to generalize the following pattern. All nodes to remove are
collected in an intermediate [forward_]list which purpose is just to be
detroyed once out of scope.
libstdc++-v3/ChangeLog:
PR libstdc++/91620
* include/bits/forward_list.tcc (forward_list<>::remove): Collect nodes
to destroy in an intermediate forward_list.
(forward_list<>::remove_if, forward_list<>::unique): Likewise.
* include/bits/list.tcc (list<>::remove, list<>::unique): Likewise.
(list<>::remove_if): Likewise.
* include/debug/forward_list (forward_list<>::_M_erase_after): Remove.
(forward_list<>::erase_after): Adapt.
(forward_list<>::remove, forward_list<>::remove_if): Collect nodes to
destroy in an intermediate forward_list.
(forward_list<>::unique): Likewise.
* include/debug/list (list<>::remove, list<>::unique): Likewise.
(list<>::remove_if): Likewise.
* testsuite/23_containers/forward_list/operations/91620.cc: New test.
* testsuite/23_containers/list/operations/91620.cc: New test.
With -pedantic the debug mode bitset has an ambiguous equality
comparison operator, because it tries to compare the non-debug base to
the debug object. The base object can be converted to another debug
bitset, making the same operator== a candidate again.
The fix is to do the comparison on both base objects, so the operator
for the derived type isn't a candidate.
For the inequality operator the same change should be done, but that
operator can be removed entirely for C++20 because it can be synthesized
by the compiler.
I don't think either equality or inequality operators are really needed,
because the public _GLIBCXX_STD_C::bitset base class cam always be
compared using its own comparison operators. I'm not changing that here
though.
libstdc++-v3/ChangeLog:
PR libstdc++/96303
* include/debug/bitset (bitset::operator==): Call _M_base() on
right operand.
(bitset::operator!=): Likewise, but don't define it at all when
default comparisons are supported by the compiler.
* testsuite/23_containers/bitset/operations/96303.cc: New test.
Make the memcmp optimization work for std::deque iterators and safe
iterators.
Co-authored-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
2020-06-08 François Dumont <fdumont@gcc.gnu.org>
Jonathan Wakely <jwakely@redhat.com>
* include/bits/deque.tcc (__lex_cmp_dit): New.
(__lexicographical_compare_aux1): Define overloads for deque
iterators.
* include/bits/stl_algobase.h (__lexicographical_compare::__3way):
New static member function.
(__lexicographical_compare<true>::__3way): Likewise.
(__lexicographical_compare<true>::__lc): Use __3way.
(__lexicographical_compare_aux): Rename to
__lexicographical_compare_aux1 and declare overloads for deque
iterators.
(__lexicographical_compare_aux): Define new forwarding function
that calls __lexicographical_compare_aux1 and declare new overloads
for safe iterators.
(lexicographical_compare): Do not use __niter_base on
parameters.
* include/debug/safe_iterator.tcc
(__lexicographical_compare_aux): Define overloads for safe
iterators.
* testsuite/25_algorithms/lexicographical_compare/1.cc: Add
checks with random access iterators.
* testsuite/25_algorithms/lexicographical_compare/deque_iterators/1.cc:
New test.
When given a type which can convert to any container-like type, the
C(const C&) copy constructor and C(const C::_Base&) converting
constructor are ambiguous. This change replaces the converting
constructor's parameter with a reference_wrapper-like type so that
calling that constructor requires an additional user-defined conversion.
This gives it a lower rank than the copy constructor, avoiding the
ambiguity.
While testing this change I discovered that __gnu_debug::forward_list
doesn't have a convering constructor from the std::forward_list base, so
this adds it.
We should probably consider whether the converting constructors should
be 'explicit' but I'm not changing that now.
libstdc++-v3/ChangeLog:
PR libstdc++/90102
* include/debug/deque (deque(const _Base&)): Replace parameter
with a struct that wraps a const _Base&.
* include/debug/forward_list (forward_list(_Base_ref)): New
constructor.
* include/debug/list (list(const _Base&)): Replace parameter
with a struct that wraps a const _Base&.
* include/debug/map.h (map(const _Base&)): Likewise.
* include/debug/multimap.h (multimap(const _Base&)): Likewise.
* include/debug/multiset.h (multiset(const _Base&)): Likewise.
* include/debug/set.h (set(const _Base&)): Likewise.
* include/debug/unordered_map (unordered_map(const _Base&))
(unordered_multimap(const _Base&)): Likewise.
* include/debug/unordered_set (unordered_set(const _Base&))
(unordered_multiset(const _Base&)): Likewise.
* testsuite/23_containers/vector/cons/destructible_debug_neg.cc:
Adjust dg-error line number.
* include/debug/vector (vector(const _Base&)): Likewise.
* testsuite/23_containers/deque/debug/90102.cc: New test.
* testsuite/23_containers/forward_list/debug/90102.cc: New test.
* testsuite/23_containers/list/debug/90102.cc: New test.
* testsuite/23_containers/map/debug/90102.cc: New test.
* testsuite/23_containers/multimap/debug/90102.cc: New test.
* testsuite/23_containers/multiset/debug/90102.cc: New test.
* testsuite/23_containers/set/debug/90102.cc: New test.
* testsuite/23_containers/unordered_map/debug/90102.cc: New test.
* testsuite/23_containers/unordered_multimap/debug/90102.cc: New test.
* testsuite/23_containers/unordered_multiset/debug/90102.cc: New test.
* testsuite/23_containers/unordered_set/debug/90102.cc: New test.
* testsuite/23_containers/vector/debug/90102.cc: New test.
The body of this function isn't just a return statement, so it can't be
constexpr until C++14.
PR libstdc++/95289
* include/debug/helper_functions.h (__get_distance): Only declare
as a constexpr function for C++14 and up.
* testsuite/25_algorithms/copy/debug/95289.cc: New test.
This appears to be a copy&paste error, which cppcheck diagnoses.
PR other/94629
* include/debug/formatter.h (_Error_formatter::_Parameter): Fix
redundant assignment in constructor.
This fixes a test failure with -D_GLIBCXX_DEBUG:
FAIL: 23_containers/array/comparison_operators/constexpr.cc (test for excess errors)
* include/debug/array (operator<=>): Define for C++20.
* testsuite/23_containers/array/tuple_interface/get_debug_neg.cc:
Adjust dg-error line numbers.
* testsuite/23_containers/array/tuple_interface/
tuple_element_debug_neg.cc: Likewise.
This fixes a test failure with -std=gnu++98 -D_GLIBCXX_DEBUG:
FAIL: 21_strings/basic_string/modifiers/insert/char/1.cc (test for excess errors)
* include/debug/string (__gnu_debug::basic_string::insert): Fix for
C++98 where the member function of the base class returns void.
This adds another chunk of the <ranges> header.
The changes from P1456R1 (Move-only views) and P1862R1 (Range adaptors
for non-copyable iterators) are included, but not the changes from
P1870R1 (forwarding-range<T> is too subtle).
The tests for subrange and iota_view are poor and should be improved.
* include/bits/regex.h (match_results): Specialize __enable_view_impl.
* include/bits/stl_set.h (set): Likewise.
* include/bits/unordered_set.h (unordered_set, unordered_multiset):
Likewise.
* include/debug/multiset.h (__debug::multiset): Likewise.
* include/debug/set.h (__debug::set): Likewise.
* include/debug/unordered_set (__debug::unordered_set)
(__debug::unordered_multiset): Likewise.
* include/std/ranges (ranges::view, ranges::enable_view)
(ranges::view_interface, ranges::subrange, ranges::empty_view)
(ranges::single_view, ranges::views::single, ranges::iota_view)
(ranges::views::iota): Define for C++20.
* testsuite/std/ranges/empty_view.cc: New test.
* testsuite/std/ranges/iota_view.cc: New test.
* testsuite/std/ranges/single_view.cc: New test.
* testsuite/std/ranges/view.cc: New test.
From-SVN: r278370
This helper function is not a valid constexpr function in C++11, so
should only be marked constexpr for C++14 and later.
* include/debug/helper_functions.h (__valid_range): Change
_GLIBCXX_CONSTEXPR to _GLIBCXX14_CONSTEXPR.
From-SVN: r277338
Avoid creating arbitrarily large objects on the stack when emplacing
trivially copyable objects into a variant. Currently we provide the
strong exception-safety guarantee for all trivially copyable types, by
constructing a second variant and then doing a non-throwing move
assignment from the temporary. This patch restricts that behaviour to
trivially copyable types that are no larger than 256 bytes. For larger
types the object will be emplaced directly into the variant, and if its
initialization throws then the variant becomes valueless.
Also implement Antony Polukhin's suggestion to whitelist specific types
that are not trivially copyable but can be efficiently move-assigned.
Emplacing those types will never cause a variant to become valueless.
The whitelisted types are: std::shared_ptr, std::weak_ptr,
std::unique_ptr, std::function, and std::any. Additionally,
std::basic_string, std::vector, and __gnu_debug::vector are whitelisted
if their allocator traits give them a non-throwing move assignment
operator. Specifically, this means std::string is whitelisted, but
std::pmr::string is not.
As part of this patch, additional if-constexpr branches are added for
the cases where the initialization is known to be non-throwing (so the
overhead of the try-catch block can be avoided) and where a scalar is
being produced by a potentially-throwing conversion operator (so that
the overhead of constructing and move-assigning a variant is avoided).
These changes should have no semantic effect, just better codegen.
PR libstdc++/87431 (again)
* include/bits/basic_string.h (__variant::_Never_valueless_alt):
Define partial specialization for basic_string.
* include/bits/shared_ptr.h (_Never_valueless_alt): Likewise for
shared_ptr and weak_ptr.
* include/bits/std_function.h (_Never_valueless_alt): Likewise for
function.
* include/bits/stl_vector.h (_Never_valueless_alt): Likewise for
vector.
* include/bits/unique_ptr.h (_Never_valueless_alt): Likewise for
unique_ptr.
* include/debug/vector (_Never_valueless_alt): Likewise for debug
vector.
* include/std/any (_Never_valueless_alt): Define explicit
specialization for any.
* include/std/variant (_Never_valueless_alt): Define primary template.
(__never_valueless): Use _Never_valueless_alt instead of
is_trivially_copyable.
(variant::emplace<N>(Args&&...)): Add special case for non-throwing
initializations to avoid try-catch overhead. Add special case for
scalars produced by potentially-throwing conversions. Use
_Never_valueless_alt instead of is_trivially_copyable for the
remaining strong exception-safety cases.
(variant::emplace<N>(initializer_list<U>, Args&&...)): Likewise.
* testsuite/20_util/variant/87431.cc: Run both test functions.
* testsuite/20_util/variant/exception_safety.cc: New test.
* testsuite/20_util/variant/run.cc: Use pmr::string instead of string,
so the variant becomes valueless.
From-SVN: r270170
There are a number of UTF-8 characters in comments which add no value
and can be replaced with ASCII equivalents, or removed entirely for the
section sign (U+00A7).
PR libstdc++/88607
* include/bits/forward_list.h: Replace UTF-8 "ligature fi" character.
* include/debug/forward_list: Likewise.
* include/experimental/bits/shared_ptr.h: Remove UTF-8 "section sign"
character.
* include/experimental/chrono: Likewise.
* include/experimental/functional: Likewise.
* include/experimental/ratio: Likewise.
* include/experimental/system_error: Likewise.
* include/experimental/tuple: Likewise.
* include/experimental/type_traits: Likewise.
* include/parallel/workstealing.h: Replace UTF-8 "en dash" character.
* include/parallel/multiseq_selection.h: Likewise.
From-SVN: r267564
2018-11-06 John Bytheway <jbytheway@gmail.com>
PR libstdc++/87872
* include/debug/safe_sequence.tcc
(_Safe_sequence<>::_M_transfer_from_if): Skip transfer to self.
From-SVN: r265851
