Define the feature test macro now that ranges support is complete.
This also changes the preprocessor checks for the __cpp_concepts macro
so that library components depending on concepts are only enabled when
C++20 concepts are supported, and not just for the Concepts TS (which
uses different syntax in places).
* include/bits/range_cmp.h (__cpp_lib_ranges): Define.
* include/bits/stl_iterator.h: Check value of __cpp_concepts so that
C++20 concepts are required.
* include/bits/stl_iterator_base_types.h: Likewise.
* include/std/concepts: Likewise.
* include/std/version: Likewise.
* testsuite/std/ranges/headers/ranges/synopsis.cc: Check feature test
macro.
This adds the missing parts of P0896R4 to reverse_iterator and
move_iterator, so that they meet the C++20 requirements. This should be
the last piece of P0896R4, meaning ranges support is now complete.
The PR 94354 bug with reverse_iterator's comparisons is fixed for C++20
only, but that change should be extended to C++11, C++14 and C++17 modes
in stage 1.
* include/bits/stl_iterator.h (reverse_iterator::iterator_concept)
(reverse_iterator::iterator_category): Define for C++20.
(reverse_iterator): Define comparison operators correctly for C++20.
(__normal_iterator): Add constraints to comparison operators for C++20.
(move_iterator::operator++(int)) [__cpp_lib_concepts]: Define new
overload for input iterators.
(move_iterator): Add constraints to comparison operators for C++20.
Define operator<=> for C++20.
* testsuite/24_iterators/move_iterator/input_iterator.cc: New test.
* testsuite/24_iterators/move_iterator/move_only.cc: New test.
* testsuite/24_iterators/move_iterator/rel_ops_c++20.cc: New test.
* testsuite/24_iterators/reverse_iterator/rel_ops_c++20.cc: New test.
std::insert_iterator and std::inserter need to be adjusted for C++20, so
that they use ranges::iterator_t. That alias template requires
ranges::begin to be defined. Rather than moving the whole of
ranges::begin (and related details like ranges::enable_borrowed_range)
into <iterator>, this defines a new, simpler version of ranges::begin
that is sufficient for ranges::iterator_t to be defined. This works
because ranges::iterator_t uses an lvalue reference type, so the logic
in ranges::begin for non-lvalue ranges (i.e. borrowed ranges) isn't
needed.
This also adds the missing constexpr specifiers to the other insert
iterators.
* include/bits/iterator_concepts.h (__detail::__decay_copy)
(__detail::__member_begin, __detail::__adl_begin): Move here from
<bits/range_access.h>.
(__detail::__ranges_begin, __detail::__range_iter_t): Define.
* bits/range_access.h (__cust_access::__decay_copy)
(__cust_access::__member_begin, __cust_access::__adl_begin): Move to
<bits/iterator_concepts.h>.
(ranges::iterator_t): Use __detail::__range_iter_t.
* include/bits/stl_iterator.h (back_insert_iterator): Simplify
conditional compilation. Add _GLIBCXX20_CONSTEXPR to all members.
(front_insert_iterator): Likewise.
(insert_iterator): Implement changes from P0896R4 for C++20.
* testsuite/24_iterators/back_insert_iterator/constexpr.cc: New test.
* testsuite/24_iterators/front_insert_iterator/constexpr.cc: New test.
* testsuite/24_iterators/headers/iterator/synopsis_c++17.cc: Adjust
for inclusion in synopsis_c++20.cc which expects different signatures
for some function templates.
* testsuite/24_iterators/insert_iterator/constexpr.cc: New test.
For C++20 the wait_until members of mutexes and condition variables are
required to be ill-formed if given a clock that doesn't meet the
requirements for a clock type. To implement that requirement this patch
adds static assertions using the chrono::is_clock trait, and defines
that trait.
To avoid expensive checks for the common cases, the trait (and
associated variable template) are explicitly specialized for the
standard clock types.
This also moves the filesystem::__file_clock type from <filesystem> to
<chrono>, so that chrono::file_clock and chrono::file_time can be
defined in <chrono> as required.
* include/bits/fs_fwd.h (filesystem::__file_clock): Move to ...
* include/std/chrono (filesystem::__file_clock): Here.
(filesystem::__file_clock::from_sys, filesystem::__file_clock::to_sys):
Define public member functions for C++20.
(is_clock, is_clock_v): Define traits for C++20.
* include/std/condition_variable (condition_variable::wait_until): Add
check for valid clock.
* include/std/future (_State_baseV2::wait_until): Likewise.
* include/std/mutex (__timed_mutex_impl::_M_try_lock_until): Likewise.
* include/std/shared_mutex (shared_timed_mutex::try_lock_shared_until):
Likewise.
* include/std/thread (this_thread::sleep_until): Likewise.
* testsuite/30_threads/condition_variable/members/2.cc: Qualify
slow_clock with new namespace.
* testsuite/30_threads/condition_variable/members/clock_neg.cc: New
test.
* testsuite/30_threads/condition_variable_any/members/clock_neg.cc:
New test.
* testsuite/30_threads/future/members/clock_neg.cc: New test.
* testsuite/30_threads/recursive_timed_mutex/try_lock_until/3.cc:
Qualify slow_clock with new namespace.
* testsuite/30_threads/recursive_timed_mutex/try_lock_until/
clock_neg.cc: New test.
* testsuite/30_threads/shared_future/members/clock_neg.cc: New
test.
* testsuite/30_threads/shared_lock/locking/clock_neg.cc: New test.
* testsuite/30_threads/shared_timed_mutex/try_lock_until/clock_neg.cc:
New test.
* testsuite/30_threads/timed_mutex/try_lock_until/3.cc: Qualify
slow_clock with new namespace.
* testsuite/30_threads/timed_mutex/try_lock_until/4.cc: Likewise.
* testsuite/30_threads/timed_mutex/try_lock_until/clock_neg.cc: New
test.
* testsuite/30_threads/unique_lock/locking/clock_neg.cc: New test.
* testsuite/std/time/traits/is_clock.cc: New test.
* testsuite/util/slow_clock.h (slow_clock): Move to __gnu_test
namespace.
It's not possible to construct a path::string_type from an allocator of
a different type. Create the correct specialization of basic_string, and
adjust path::_S_str_convert to use a basic_string_view so that it is
independent of the allocator type.
PR libstdc++/94242
* include/bits/fs_path.h (path::_S_str_convert): Replace first
parameter with basic_string_view so that strings with different
allocators can be accepted.
(path::generic_string<C,T,A>()): Use basic_string object that uses the
right allocator type.
* testsuite/27_io/filesystem/path/generic/94242.cc: New test.
* testsuite/27_io/filesystem/path/generic/generic_string.cc: Improve
test coverage.
Clang 9 supports C++20 via -std=c++2a but doesn't support Concepts, so
several of the new additions related to the Ranges library fail to
compile with -std=c++2a. The new definition of iterator_traits and the
definition of default_sentinel_t are guarded by __cpp_lib_concepts, so
check that in addition to __cplusplus > 201703L.
* include/bits/stl_algobase.h (__lexicographical_compare_aux): Check
__cpp_lib_concepts before using iter_reference_t.
* include/bits/stream_iterator.h (istream_iterator): Check
__cpp_lib_concepts before using default_sentinel_t.
* include/bits/streambuf_iterator.h (istreambuf_iterator): Likewise.
This works around PR 93978 by avoiding having to instantiate the body of
ranges::empty() when checking the constraints of view_interface::operator
bool(). When ranges::empty() has an auto return type, then we must instantiate
its body in order to determine whether the requires expression {
ranges::empty(_M_derived()); } is well-formed. But this means instantiating
view_interface::empty() and hence view_interface::_M_derived(), all before we've
yet deduced the return type of join_view::end(). (The reason
view_interface::operator bool() is needed in join_view::end() in the first place
is because in this function we perform direct initialization of
join_view::_Sentinel from a join_view, and so we try to find a conversion
sequence from the latter to the former that goes through this conversion
operator.)
Giving ranges::empty() a concrete return type of bool should be safe according
to [range.prim.empty]/4 which says "whenever ranges::empty(E) is a valid
expression, it has type bool."
This fixes the test case in PR 93978 when compiling without -Wall, but with -Wall
the test case still fails due to the issue described in PR c++/94038, I think.
I still don't quite understand why the test case doesn't fail without -O.
libstdc++-v3/ChangeLog:
PR libstdc++/93978
* include/bits/range_access.h (__cust_access::_Empty::operator()):
Declare return type to be bool instead of auto.
* testsuite/std/ranges/adaptors/93978.cc: New test.
The discussion of iterator_traits<volatile T*>::value_type and the
example with three tempalte arguments related to an earlier version of
the patch, not the one committed.
Also improve the comment on __memcmpable.
* include/bits/cpp_type_traits.h (__memcpyable): Fix comment.
When deciding whether to perform the memset optimization in ranges::fill_n, we
were crucially neglecting to check that the output pointer's value type is a
byte type. This patch adds such a check to the problematic condition in
ranges::fill_n.
At the same time, this patch relaxes the overly conservative
__is_byte<_Tp>::__value check that requires the fill type be a byte type. It's
overly conservative because it means we won't enable the memset optimization in
the following example
char c[100];
ranges::fill(c, 37);
because the fill type is deduced to be int here. Rather than requiring that the
fill type be a byte type, it seems safe to just require the fill type be an
integral type, which is what this patch does.
libstdc++-v3/ChangeLog:
PR libstdc++/94017
* include/bits/ranges_algobase.h (__fill_n_fn::operator()): Refine
condition for when to use memset, making sure to additionally check that
the output pointer's value type is a non-volatile byte type. Instead of
requiring that the fill type is a byte type, just require that it's an
integral type.
* testsuite/20_util/specialized_algorithms/uninitialized_fill/94017.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/94017.cc:
New test.
* testsuite/25_algorithms/fill/94013.cc: Uncomment part that was blocked
by PR 94017.
* testsuite/25_algorithms/fill/94017.cc: New test.
* testsuite/25_algorithms/fill_n/94017.cc: New test.
This adds support for move-only input iterators in the ranges::unitialized_*
algorithms defined in <memory>, as per LWG 3355. The only changes needed are to
add calls to std::move in the appropriate places and to use operator- instead of
ranges::distance because the latter cannot be used with a move-only iterator
that has a sized sentinel, as is the case here. (This issue with
ranges::distance is LWG 3392.)
libstdc++-v3/ChangeLog:
LWG 3355 The memory algorithms should support move-only input iterators
introduced by P1207
* include/bits/ranges_uninitialized.h
(__uninitialized_copy_fn::operator()): Use std::move to avoid attempting
to copy __ifirst, which could be a move-only input iterator. Use
operator- instead of ranges::distance to compute distance from a sized
sentinel.
(__uninitialized_copy_n_fn::operator()): Likewise.
(__uninitialized_move_fn::operator()): Likewise.
(__uninitialized_move_n_fn::operator()): Likewise.
(__uninitialized_destroy_fn::operator()): Use std::move to avoid
attempting to copy __first.
(__uninitialized_destroy_n_fn::operator()): Likewise.
* testsuite/20_util/specialized_algorithms/destroy/constrained.cc:
Augment test.
* .../specialized_algorithms/uninitialized_copy/constrained.cc:
Likewise.
* .../specialized_algorithms/uninitialized_move/constrained.cc:
Likewise.
We are passing a value type as the first argument to is_nothrow_assignable_v,
but the result of that is inevitably false. Since this predicate is a part of
the condition that guards the corresponding optimizations for these algorithms,
this bug means these optimizations are never used. We should be passing a
reference type to is_nothrow_assignable_v instead.
libstdc++-v3/ChangeLog:
* include/bits/ranges_uninitialized.h
(uninitialized_copy_fn::operator()): Pass a reference type as the first
argument to is_nothrow_assignable_v.
(uninitialized_copy_fn::operator()): Likewise.
(uninitialized_move_fn::operator()): Likewise. Return an in_out_result
with the input iterator stripped of its move_iterator.
(uninitialized_move_n_fn::operator()): Likewise.
(uninitialized_fill_fn::operator()): Pass a reference type as the first
argument to is_nothrow_assignable_v.
(uninitialized_fill_n_fn::operator()): Likewise.
Several algorithms check the is_trivially_copyable trait to decide
whether to dispatch to memmove or memcmp as an optimization. Since
r271435 (CWG DR 2094) the trait is true for volatile-qualified scalars,
but we can't use memmove or memcmp when the type is volatile. We need to
also check for volatile types.
This is complicated by the fact that in C++20 (but not earlier standards)
iterator_traits<volatile T*>::value_type is T, so we can't just check
whether the value_type is volatile.
The solution in this patch is to introduce new traits __memcpyable and
__memcmpable which combine into a single trait the checks for pointers,
the value types being the same, and the type being trivially copyable
but not volatile-qualified.
PR libstdc++/94013
* include/bits/cpp_type_traits.h (__memcpyable, __memcmpable): New
traits to control when to use memmove and memcmp optimizations.
(__is_nonvolatile_trivially_copyable): New helper trait.
* include/bits/ranges_algo.h (__lexicographical_compare_fn): Do not
use memcmp optimization with volatile data.
* include/bits/ranges_algobase.h (__equal_fn): Use __memcmpable.
(__copy_or_move, __copy_or_move_backward): Use __memcpyable.
* include/bits/stl_algobase.h (__copy_move_a2): Use __memcpyable.
(__copy_move_backward_a2): Likewise.
(__equal_aux1): Use __memcmpable.
(__lexicographical_compare_aux): Do not use memcmp optimization with
volatile data.
* testsuite/25_algorithms/copy/94013.cc: New test.
* testsuite/25_algorithms/copy_backward/94013.cc: New test.
* testsuite/25_algorithms/equal/94013.cc: New test.
* testsuite/25_algorithms/fill/94013.cc: New test.
* testsuite/25_algorithms/lexicographical_compare/94013.cc: New test.
* testsuite/25_algorithms/move/94013.cc: New test.
* testsuite/25_algorithms/move_backward/94013.cc: New test.
As noted in LWG 3410 the specification in the C++20 draft performs more
iterator comparisons than necessary when the end of either range is
reached. Our implementation followed that specification. This removes
the redundant comparisons so that we do no unnecessary work as soon as
we find that we've reached the end of either range.
The odd-looking return statement is because it generates better code
than the original version that copied the global constants.
* include/bits/stl_algobase.h (lexicographical_compare_three_way):
Avoid redundant iterator comparisons (LWG 3410).
The new 25_algorithms/lexicographical_compare/93972.cc test fails on
targets where char is unsigned, revealing an existing regression with
the std::__memcmp helper that had gone unnoticed in
std::lexicographical_compare. When comparing char and unsigned char, the
memcmp optimisation is enabled, but the new std::__memcmp function fails
to compile for mismatched types.
PR libstdc++/93972
* include/bits/stl_algobase.h (__memcmp): Allow pointer types to
differ.
* testsuite/25_algorithms/lexicographical_compare/uchar.cc: New test.
Move std::is_permutation algorithm with associated helpers to stl_algobase.h
to remove stl_algo.h include from hashtable_policy.h and so reduce preprocess
size of unordered_map and unordered_set headers.
* include/bits/stl_algo.h
(__find_if, __count_if, __is_permutation, std::is_permutation): Move...
* include/bits/stl_algobase.h: ...here.
* include/bits/hashtable_policy.h: Remove <bits/stl_algo.h> include.
We were enabling the memcmp optimization in ranges::lexicographical_compare for
signed integral types and for integral types wider than a byte. But memcmp
gives the wrong answer for arrays of such types. This patch fixes this issue by
refining the condition that enables the memcmp optimization. It's now
consistent with the corresponding condition used in
std::lexicographical_compare.
libstdc++-v3/ChangeLog:
PR libstdc++/93972
* include/bits/ranges_algo.h (__lexicographical_compare_fn::operator()):
Fix condition for when to use memcmp, making it consistent with the
corresponding condition used in std::lexicographical_compare.
* testsuite/25_algorithms/lexicographical_compare/93972.cc: New test.
Although most of the old-style "concept checks" are only really usable
with C++98 because they enforce the wrong things, this is a simple
change that makes them a bit more useful for C++14 and up.
* include/bits/boost_concept_check.h (__function_requires): Add
_GLIBCXX14_CONSTEXPR.
* testsuite/25_algorithms/min/concept_checks.cc: New test.
* include/bits/ranges_algo.h (__lexicographical_compare_fn): Declare
variables in smaller scope and avoid calling ranges::distance when we
know they are pointers. Remove statically-unreachable use of
__builtin_unreachable().
* include/bits/stl_algobase.h (__lexicographical_compare::__lc):
Define inline.
The mutating sequence algorithms std::copy, std::copy_backward,
std::move and std::move_backward conditionally use __builtin_memmove
for trivially copyable types. However, because memmove isn't usable in
constant expressions the use of __builtin_memmove is wrapped in a
__memmove function which replaces __builtin_memmove with a handwritten
loop when std::is_constant_evaluated() is true.
This means we have a manual loop for non-trivially copyable cases, and a
different manual loop for trivially copyable but constexpr cases. The
latter loop has incorrect semantics for the {copy,move}_backward cases
and so isn't used for them. Until earlier today the latter loop also had
incorrect semantics for the std::move cases, trying to move from const
rvalues.
The approach taken by this patch is to remove the __memmove function
entirely and use the original (and correct) manual loops for the
constexpr cases as well as the non-trivially copyable cases. This was
already done for move_backward and copy_backward, but was incorrectly
turning copy_backward into move_backward, by failing to use the _IsMove
constant to select the right specialization. This patch also fixes that.
* include/bits/ranges_algobase.h (__copy_or_move): Do not use memmove
during constant evaluation. Call __builtin_memmove directly instead of
__memmove.
(__copy_or_move_backward): Likewise.
* include/bits/stl_algobase.h (__memmove): Remove.
(__copy_move<M, true, random_access_iterator_tag>::__copy_m)
(__copy_move_backward<M, true, random_access_iterator_tag>::__copy_m):
Use __builtin_memmove directly instead of __memmove.
(__copy_move_a2): Do not use memmove during constant evaluation.
(__copy_move_backward_a2): Use _IsMove constant to select correct
__copy_move_backward specialization.
* testsuite/25_algorithms/copy_backward/constexpr.cc: Check for copies
begin turned into moves during constant evaluation.
The std::move and std::move_backward algorithms dispatch to the
std::__memmove helper when appropriate. That function uses a
pointer-to-const for the source values, preventing them from being
moved. The two callers of that function have the same problem.
Rather than altering __memmove and its callers to work with const or
non-const source pointers, this takes a more conservative approach of
casting away the const at the point where we want to do a move
assignment. This relies on the fact that we only use __memmove when the
type is trivially copyable, so we know the move assignment doesn't alter
the source anyway.
PR libstdc++/93872
* include/bits/stl_algobase.h (__memmove): Cast away const before
doing move assignment.
* testsuite/25_algorithms/move/93872.cc: New test.
* testsuite/25_algorithms/move_backward/93872.cc: New test.
This adds some missing pieces of the Ranges TS that make back_insert_iterator and
front_insert_iterator conform to the new output_iterator requirements.
It also fixes a bug in ranges::__copy_or_move and
ranges::__copy_or_move_backward in which we were inspecting the iter_value_t of
the output iterator, but output iterators such as back_insert_iterator and
front_insert_iterator whose value_type = void do not have an iter_value_t
according to [readable.traits] p4. The entire __use_memmove condition should
probably be rewritten, but the simplest fix for now is to inspect the
iterator_traits of the output iterator instead.
libstdc++-v3/ChangeLog:
PR libstdc++/93884
* include/bits/ranges_algobase.h (__copy_or_move,
__copy_or_move_backward): Don't inspect the iter_value_t of the output
iterator, instead inspect its iterator_traits directly.
* include/bits/stl_iterator.h (back_insert_iterator::container):
Conditionally initialize.
(back_insert_iterator::difference_type): Conditionally define.
(back_insert_iterator::back_insert_iterator): Conditionally define this
default constructor.
(front_insert_iterator::container): Conditionally initialize.
(front_insert_iterator::difference_type): Conditionally define.
(front_insert_iterator::front_insert_iterator): Conditionally define
this default constructor.
* 24_iterators/back_insert_iterator/pr93884.cc: New test.
* 24_iterators/front_insert_iterator/pr93884.cc: New test.
This patch adds std::shift_left and std::shift_right as per P0769R2. Alhough
these are STL-style algos, this patch places them in <bits/ranges_algo.h>
because they make use of some functions in the ranges namespace that are more
easily reachable from <bits/ranges_algo.h> than from <bits/stl_algo.h>, namely
ranges::next. In order to place these algos in <bits/stl_algo.h>, we would need
to include <bits/range_access.h> from <bits/stl_algo.h> which would undesirably
increase the size of <bits/stl_algo.h>.
libstdc++-v3/ChangeLog:
P0769R2 Add shift to <algorithm>
* include/bits/ranges_algo.h (shift_left, shift_right): New.
* testsuite/25_algorithms/shift_left/1.cc: New test.
* testsuite/25_algorithms/shift_right/1.cc: New test.
Somehow I missed that the _M_value member can throw on construction.
* include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
Make noexcept-specifier conditional.
* testsuite/24_iterators/istream_iterator/cons/sentinel.cc: Check
noexcept-specifier.
Missing pieces of P0896R4 "The One Ranges Proposal" for C++20.
* include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
Add constructor.
(operator==(istream_iterator, default_sentinel_t)): Add operator.
(ostream_iterator::difference_type): Define to ptrdiff_t for C++20.
* include/bits/streambuf_iterator.h
(istreambuf_iterator(default_sentinel_t)): Add constructor.
(operator==(istreambuf_iterator, default_sentinel_t)): Add operator.
* testsuite/24_iterators/istream_iterator/cons/sentinel.cc:
New test.
* testsuite/24_iterators/istream_iterator/sentinel.cc: New test.
* testsuite/24_iterators/istreambuf_iterator/cons/sentinel.cc:
New test.
* testsuite/24_iterators/istreambuf_iterator/sentinel.cc: New test.
This changes how arrays of unknown bound and/or incomplete element type
are handled.
* include/bits/range_access.h (ranges::begin): Reject array of
incomplete type.
(ranges::end, ranges::size): Require arrays to be bounded.
(ranges::data): Require lvalue or borrowed_range.
(ranges::iterator_t): Remove constraint.
* testsuite/std/ranges/access/begin.cc: Do not check array of
incomplete type.
* testsuite/std/ranges/access/begin_neg.cc: New test.
* testsuite/std/ranges/access/end_neg.cc: Adjust expected error.
* testsuite/std/ranges/access/size_neg.cc: Adjust expected error.
* testsuite/std/ranges/access/ssize.cc: Do not check array of
incomplete type.
* 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.
Some of these casts were added by me the other day, but some were
already present. I think they are all redundant following the
introduction of the boolean-testable concept in P1964R2.
* include/bits/ranges_algo.h (__find_fn, __find_first_of_fn)
(__adjacent_find_fn, __remove_if_fn, __remove_copy_if_fn)
(__unique_fn, __unique_copy_fn): Remove redundant conversions to bool.
libstdc++-v3/ChangeLog:
P2106R0 Alternative wording for GB315 and GB316
* include/bits/ranges_algo.h (in_fun_result): New.
(for_each_result, for_each_n_result): Change into an alias of
in_fun_result.
(in_in_result): New.
(mismatch_result): Change into an alias of in_in_result.
(copy_if_result): Change into an alias of in_out_result.
(swap_ranges_result): Change into an alias of in_in_result.
(unary_transform_result): Change into an alias of in_out_result.
(in_in_out_result): New.
(binary_transform_result): Change into an alias of in_in_out_result.
(replace_copy_result, replace_copy_if_result, remove_copy_if_result,
remove_copy_result, unique_copy_result, reverse_copy_result,
rotate_copy_result, partial_sort_copy_result): Change into an alias of
in_out_result.
(in_out_out_result): New.
(partition_copy_result, merge_result): Change into an alias of
in_out_out_result.
(set_union_result, set_intersection_result): Change into an alias of
in_in_out_result.
(set_difference_result): Change into an alias of in_out_result.
(set_symmetric_difference): Change into an alias of in_in_out_result.
(min_max_result): New.
(minmax_result, minmax_element_result): Change into an alias of
min_max_result.
(in_found_result): New.
(next_permutation_result, prev_permutation_result): Change into an alias
of in_found_result.
(__next_permutation_fn::operator(), __prev_permutation_fn::operator()):
Adjust following changes to next_permutation_result and
prev_permutation_result.
* include/bits/ranges_algobase.h (in_out_result): New.
(copy_result, move_result, move_backward_result, copy_backward_result,
copy_n_result): Change into an alias of in_out_result.
* include/bits/ranges_uninitialized.h (uninitialized_copy_result,
uninitialized_copy_n_result, uninitialized_move_result,
uninitialized_move_n_result): Likewise.
* testsuite/25_algorithms/next_permutation/constrained.cc: Adjust uses of
structured bindings.
* testsuite/25_algorithms/prev_permutation/constrained.cc: Likewise.
This adds rangified overloads for for_each_n, sample and clamp as per P1243R4.
libstdc++-v3/ChangeLog:
P1243R4 Rangify new algorithms
* include/bits/ranges_algo.h (for_each_n_result, __for_each_n_fn,
for_each_n, __sample_fn, sample, __clamp_fn, clamp): New.
* testsuite/25_algorithms/clamp/constrained.cc: New test.
* testsuite/25_algorithms/for_each/constrained.cc: Augment test.
* testsuite/25_algorithms/sample/constrained.cc: New test.
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.
This defines ranges::ssize as approved in Prague. It's unclear what is
supposed to happen for types for which range_difference_t is not a valid
type. I've assumed they are not meant to be usable with ranges::ssize,
despite being usable with ranges::size.
* include/bits/range_access.h (_SSize, ssize): Define for C++20.
* testsuite/std/ranges/access/ssize.cc: New test.
Implement this change for C++20 that was just approved in Prague.
P1956R1 On the names of low-level bit manipulation functions
* include/bits/hashtable_policy.h: Update comment.
* include/std/bit (__ispow2, __ceil2, __floor2, __log2p1): Rename.
(ispow2, ceil2, floor2, log2p1): Likewise.
(__cpp_lib_int_pow2): Add feature test macro.
* include/std/charconv (__to_chars_len_2): Adjust use of __log2p1.
* include/std/memory (assume_aligned): Adjust use of ispow2.
* include/std/version (__cpp_lib_int_pow2): Add.
* libsupc++/new_opa.cc: Adjust use of __ispow2.
* src/c++17/memory_resource.cc: Likewise, and for __ceil2 and __log2p1.
* testsuite/17_intro/freestanding.cc: Adjust use of ispow2.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_ceil.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_ceil_neg.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_floor.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_width.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/has_single_bit.cc: ... here.
In C++20 <memory> depends on <bits/ranges_unitialized.h> which
depends on <bits/random.h> just for a single concept. Including
<bits/random.h> also requires including <cmath>, which is huge due to
the C++17 special functions.
This change moves the concept to the <bits/uniform_int_dist.h> internal
header that exists so that <bits/stl_algobase.h> doesn't need to include
<bits/random.h>.
PR libstdc++/92546 (partial)
* include/bits/random.h (uniform_random_bit_generator): Move definition
to <bits/uniform_int_dist.h>.
* include/bits/ranges_algo.h: Include <bits/uniform_int_dist.h> instead
of <bits/random.h>.
* include/bits/ranges_algobase.h: Do not include <cmath>.
* include/bits/uniform_int_dist.h (uniform_random_bit_generator):
Move here.
* include/std/ranges: Do not include <limits>.
* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.
Many uses of std::numeric_limits in C++17 and C++20 features only really
need the min(), max() and digits constants for integral types. By adding
__detail::__int_limits we can avoid including the whole <limits> header.
The <limits> header isn't especially large, but avoiding it still gives
small savings in compilation time and memory usage for the compiler.
There are also C++11 features that could benefit from this change (e.g.
<bits/hashtable_policy.h> and <bits/uniform_int_dist.h>) but I won't
change those until stage 1.
The implementation of __int_limits assumes two's complement integers,
which is true for all targets supported by GCC.
PR libstdc++/92546 (partial)
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/bits/int_limits.h: New header.
* include/bits/parse_numbers.h (__select_int::_Select_int): Replace
numeric_limits with __detail::__int_limits.
* include/std/bit (__rotl, __rotr, __countl_zero, __countl_one)
(__countr_zero, __countr_one, __popcount, __ceil2, __floor2, __log2p1):
Likewise.
* include/std/charconv (__to_chars_8, __from_chars_binary)
(__from_chars_alpha_to_num, from_chars): Likewise.
* include/std/memory_resource (polymorphic_allocator::allocate)
(polymorphic_allocator::allocate_object): Likewise.
* include/std/string_view (basic_string_view::_S_compare): Likewise.
* include/std/utility (in_range): Likewise.
* testsuite/20_util/integer_comparisons/in_range_neg.cc: Adjust for
extra error about incomplete type __int_limits<bool>.
* testsuite/26_numerics/bit/bit.count/countl_one.cc: Include <limits>.
* testsuite/26_numerics/bit/bit.count/countl_zero.cc: Likewise.
* testsuite/26_numerics/bit/bit.count/countr_one.cc: Likewise.
* testsuite/26_numerics/bit/bit.count/countr_zero.cc: Likewise.
* testsuite/26_numerics/bit/bit.count/popcount.cc: Likewise.
* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Likewise.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Likewise.
* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Likewise.
* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Likewise.
* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Likewise.
* testsuite/26_numerics/bit/bit.rotate/rotl.cc: Likewise.
* testsuite/26_numerics/bit/bit.rotate/rotr.cc: Likewise.
This avoids instantiating dead code when the true branch of the constexpr if is
taken.
libstdc++-v3/ChangeLog:
* include/bits/ranges_algo.h (__lexicographical_compare_fn::operator()):
Move code after an early exit constexpr if to under an else branch.
* include/bits/ranges_algobase.h (__equal_fn::operator()): Likewise.
These subroutines have only a single call site, so it might be best and simplest
to eliminate them before we convert the algos into function objects.
libstdc++-v3/ChangeLog:
* include/bits/ranges_algo.h (ranges::__find_end): Fold into ...
(ranges::find_end): ... here.
(ranges::__lexicographical_compare): Fold into ...
(ranges::lexicographical_compare): ... here.
* include/bits/ranges_algobase.h (ranges::__equal): Fold into ...
(ranges::equal): ... here.
Now that this feature has been approved for C++20 we can define the
macro to the official value.
* include/bits/erase_if.h (__cpp_lib_erase_if): Define to 202002L.
* 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/23_containers/deque/erasure.cc: Test for new value.
* 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.
* include/bits/random.h (uniform_random_bit_generator): Require min()
and max() to be constant expressions and min() to be less than max().
* testsuite/26_numerics/random/concept.cc: Check additional cases.
* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.
This implements all the ranges members defined in [specialized.algorithms]:
ranges::uninitialized_default_construct
ranges::uninitialized_value_construct
ranges::uninitialized_copy
ranges::uninitialized_copy_n
ranges::uninitialized_move
ranges::uninitialized_move_n
ranges::uninitialized_fill
ranges::uninitialized_fill_n
ranges::construct_at
ranges::destroy_at
ranges::destroy
It also implements (hopefully correctly) the "obvious" optimizations for these
algos, namely that if the output range has a trivial value type and if the
appropriate operation won't throw then we can dispatch to the standard ranges
version of the algorithm which will then potentially enable further
optimizations.
libstdc++-v3/ChangeLog:
* include/Makefile.am: Add <bits/ranges_uninitialized.h>.
* include/Makefile.in: Regenerate.
* include/bits/ranges_uninitialized.h: New header.
* include/std/memory: Include it.
* testsuite/20_util/specialized_algorithms/destroy/constrained.cc: New
test.
* .../uninitialized_copy/constrained.cc: New test.
* .../uninitialized_default_construct/constrained.cc: New test.
* .../uninitialized_fill/constrained.cc: New test.
* .../uninitialized_move/constrained.cc: New test.
* .../uninitialized_value_construct/constrained.cc: New test.
This roughly mirrors the existing split between <bits/stl_algo.h> and
<bits/stl_algobase.h>. The ranges [specialized.algorithms] will use this new
header to avoid including all of of <bits/ranges_algo.h>.
libstdc++-v3/ChangeLog:
* include/Makefile.am: Add bits/ranges_algobase.h
* include/Makefile.in: Regenerate.
* bits/ranges_algo.h: Include <bits/ranges_algobase.h> and refactor
existing #includes.
(__detail::__is_normal_iterator, __detail::is_reverse_iterator,
__detail::__is_move_iterator, copy_result, move_result,
__equal, equal, copy_result, move_result, move_backward_result,
copy_backward_result, __copy_or_move_backward, __copy_or_move, copy,
move, copy_backward, move_backward, copy_n_result, copy_n, fill_n,
fill): Split out into ...
* bits/range_algobase.h: ... this new header.
libstdc++-v3/ChangeLog:
LWG 3389 and LWG 3390
* include/bits/stl_iterator.h (move_move_iterator): Use std::move when
constructing the move_iterator with __i.
(counted_iterator::counted_iterator): Use std::move when initializing
M_current with __i.
* testsuite/24_iterators/counted_iterator/lwg3389.cc: New test.
* testsuite/24_iterators/move_iterator/lwg3390.cc: New test.
