`iter_value_t` doesn't detour through `iterator_traits`, so it can be valid for non-iterator types. This breaks `_Is_Source2`, however, which expects `_Iter_value_t` to filter out non-iterator types.
Drive-by: rename `_Is_Source2` to `_Is_Source_impl` to be consistent with how we name trait helpers elsewhere.
Fixes DevCom-953628.
* Allow Clang10 in the STL
This PR includes changes necessary to allow (but not require) clang 10 in the STL. It also includes test changes to allow the tests to pass given new clang warnings for deprecated behaviors, and an update to the LLVM reference to get similar changes that have been applied upstream to libc++ tests.
Details:
* In `<compare>`, remove workarounds for LLVM-41991 in Clang 10 RC1 fixed in RC2.
* In `<concepts>`, remove `_SILENCE_CLANG_CONCEPTS_MESSAGE`.
* In `<queue>` and `<stack>`, befriend only corresponding specializations of operator templates.
* In `<system_error>`, fix the `__cpp_constexpr_dynamic_alloc` implementation of `_Immortalize_memcpy_image` (which we apparently didn't review at all).
* In `<experimental/filesystem>`, apply a fix equivalent to the resolution of LWG-3244.
* Update `P0220R1_optional` from upstream.
* In `P0595R2_is_constant_evaluated`, silence Clang's warning for using `is_constant_evaluated` in a manifestly constant-evaluated context.
* In `P0896R4_ranges_iterator_machinery`, fix bogus test cases that were expecting VSO-1008447, silence "unused variable" warnings, and avoid taking advantage of too-lenient MSVC comparison rewrite behavior.
* In `P0896R4_ranges_range_machinery`, silence "unused variable" warning.
* In `P0898R3_concepts`, Remove workaround for LLVM-44627 in Clang 10 RC1 fixed in RC2.
* In `VSO_0000000_type_traits` and `tr1/type_traits5`, silence volatile function parameter deprecation warnings.
* In `tr1/condition_variable`, `tr1/regex1`, and `tr1/regex3`, remove unnecessary copy assignment operators that were prompting Clang warnings about the implicitly definition of a copy constructor for such a class being deprecated.
* In `tr1/csetjmp`, silence volatile increment deprecation warnings.
Skip new libc++ tests:
* Various `span` tests that expect `const_iterator` (libc++ doesn't yet implement LWG-3320)
* tests for the implementation of P1135R6 "The C++ Synchronization Library" which we do not yet implement
Resolves GH-615 / DevCom-950424.
* Extract _Is_file_not_found to <xfilesystem_abi.h> as __std_is_file_not_found because we also need that in filesystem.cpp.
* Add ERROR_BAD_NETPATH to __std_is_file_not_found.
* Map ERROR_BAD_NETPATH to errc::no_such_file_or_directory.
* Change filesystem tests that look for file not exists behavior to also test bad network paths.
Rename the variable template `disable_sized_sentinel` to `disable_sized_sentinel_for` for consistency with the name of the associated concept `sized_sentinel_for`.
Addresses #39.
When `defined(__cpp_lib_concepts)`, `(back_|front_|)insert_iterator` are default constructible, and have `ptrdiff_t` as difference type.
Skip libc++ tests broken by this change.
This change removes the last "nonessential" stack frame that would be encountered for threads, and makes the debugging experience for several standard components, like `std::function`, nicer by not needing so many step into / step out of sequences.
1. CRT's thread entry point
2. std::thread's entry point that staples the parameters on
3. invoke
4. already user code yay!
Hopefully this makes debug codegen better too, particularly now that ranges hammers invoke even harder than we used to.
I didn't change any of the metaprogramming for deciding which strategy to use -- I like that we don't use SFINAE to make that decision, and don't really consider myself competent enough a metaprogrammer to confidently make changes there. I just make `_Invoker_xyz` also supply a strategy value that is fed into `if constexpr`. @CaseyCarter suggested some larger changes which might have sped up metaprogramming I tried, but ran into issues because one can't deduce the calling convention of pointers-to-member-function.
I've also made a one time exception to our usual policy of using `std::forward` rather than `static_cast`, with the rationale that `invoke` is hammered *everywhere*, and also by traits, and we want the debugging experience of that to be as nice as possible.
(Also drive-by removed unnecessary compilation of iostreams from the `Dev10_729003_bind_reference_wrapper` I noticed debugging a test case failure)
Co-authored-by: Casey Carter <cartec69@gmail.com>
* Several range algorithms
In `<algorithm>`, implement:
* the generic algorithm result types from P2106R0 (lines 75-227)
* `ranges::for_each` and its result alias `for_each_result` (lines 289-322)
* `ranges::for_each_n` and its result alias `for_each_result_n` (lines 324-351) from P1243R4
* `ranges::find` (lines 353-384)
* `ranges::find_if` (lines 396-426)
* `ranges::find_if_not` (lines 454-484)
* `ranges::count` (lines 526-568)
* `ranges::count_if` (lines 587-617)
* `ranges::mismatch` and its result alias `mismatch_result` (lines 798-891)
* `ranges::equal` (lines 893-980)
* `ranges::all_of` (lines 1006-1033)
* `ranges::any_of` (lines 1060-1087)
* `ranges::none_of` (lines 1114-1141)
* `ranges::copy` and its result alias `copy_result` (lines 1143-1175)
* `ranges::copy_n` and its result alias `copy_n_result` (lines 1177-1207)
* `ranges::copy_if` and its result alias `copy_if_result` (lines 1262-1302)
In `<concepts>`:
* implement LWG-3194 which includes the resolution of LWG-3151 (lines 51-53)
* LWG-3175 has been merged, remove conditional implementation (line 183)
* replace `boolean` concept with _`boolean-testable`_ concept from P1964R2 (lines 198-237, 283)
* move `movable` (pun intended) into synopsis order (lines 254-256)
* Modify concept `copyable` per P2102R0 (lines 260-261)
* Implement concept `equivalence_relation` from P1716R3 (lines 290-293)
In `<xutility>`:
* promote `identity` from `<functional>` for visibility in `<algorithm>` (lines 160-168)
* promote `common_range` from `<ranges>` for visibility in `<algorithm>` (lines 3091-3095)
* remove LWG-3247 and LWG-3299 annotations (lines 622, 626, and 963)
* prefix `indirectly_` to the names of `readable_traits`, `readable`, and `writable` (a great many lines); and modify `iter_value_t` (lines 366-367), `iter_reference_t` (lines ), `iter_difference_t`, `iter_rvalue_reference_t`, `indirectly_readable` (lines 688-701) and `indirectly_swappable` per P1878R1
* define alias template `_Make_unsigned_like_t` to implement P1522R1's _`make-unsigned-like-t`_ (it does nothing interesting yet, since we provide no integer-class types) (lines 727-729)
* implement the "Indirect callable" concepts `indirectly_unary_invocable`, `indirectly_regular_unary_invocable`, `indirect_unary_predicate`, `indirect_binary_predicate`, `indirect_equivalence_relation`, `indirect_strict_weak_order`, and helpers `indirect_result_t` and `projected` (lines 852-926)
* implement `indirectly_copyable` and `indirectly_copyable_storable` concepts (lines 939-952)
* implement `indirectly_swappable`, `indirectly_comparable`, `permutable`, `mergeable`, and `sortable` concepts (lines 1032-1061)
* rename `safe_range` and `enable_safe_range` to `borrowed_range` and `enable_borrowed_range` per LWG-3379 (lines 2168-2173 and 2327-2330)
* remove "Implements D2091R0" comments (various lines in 2175-2710)
* add `ranges::data` to the list of access CPOs that hard error for arrays of incomplete element types (lines 2204-2205 and 2277-2278)
* `ranges::empty` rejects arrays of unbound bound per P2091R0 (lines 2664-2692)
* implement concept `_Not_same_as` (the exposition-only _`not-same-as`_ from the working draft) (lines 3087-3089)
* implement `ranges::dangling` (lines 3097-3102)
* implement `ranges::borrowed_iterator_t` (lines 3104-3106)
In `<yvals_core.h>`:
* Indicate implementation of:
* P1207R4 Movability of Single-Pass Iterators
* P1248R1 Fixing Relations
* P1474R1 Helpful Pointers For contiguous_iterator
* P1716R3 Range Comparison Algorithms Are Over-Constrained
* P1878R1 Constraining Readable Types
* P1964R2 Replacing `boolean` with _`boolean-testable`_
* P2091R0 Fixing Issues With Range Access CPOs
* P2102R0 Make "implicit expression variations" More Explicit
* and partial implementation of:
* P1243R4 Rangify New Algorithms
* remove conditional definition of `_HAS_STD_BOOLEAN` (we never has `std::boolean` now)
`tests/std/include/instantiate_algorithms.hpp`:
* define non-movable type `Immobile`, and use it to ensure that standard algorithms neither copy nor move random number generators nor uniform random bit generators
Add header `tests/std/include/range_algorithm_support.hpp` with support machinery for the ranges algorithm tests. It notably defines:
* `is_permissive` for determining whether we are compiling in MSVC's permissive mode (lines 18-37)
* A class template `borrowed<bool>` whose specializations always model `range` and model `borrowed_range` iff the template parameter is `true` (lines 39-46)
* Function objects `get_first` and `get_second` which project the pertinent member from `pair` arguments (lines 48-54)
* A class template `move_only_range<T>` which adapts a `contiguous_range` of `T` into a move-only `view` with move-only `input_iterator`s (lines 56-150)
* A "phony" iterator class template `test_iterator` with tunable category, value type, and difference capability for instantiation tests (lines 152-363)
* A similar "phony" class template `test_range` with tunable category, size, and commonality (i.e., is the sentinel type the same as the iterator type) (lines 365-423)
* "phony" predicate and projection types for instantiation tests (lines 425-442)
* combinatoric instantiation machinery for instantiation tests that instantiate with all interesting kinds of output iterators or input ranges (lines 444-529)
A new compile-only test `tests/std/tests/P0896R4_ranges_algorithm_machinery` which covers:
* `indirectly_unary_invocable`/`indirectly_regular_unary_invocable`
* `indirect_unary_predicate`/`indirect_binary_predicate`/`indirect_result_t`
* `projected`
* `indirectly_copyable`/`indirectly_swappable`/`indirectly_comparable`
* `dangling`/`borrowed_iterator_t`
* the result types `in_found_result`/`in_fun_result`/`in_in_result`/`in_out_result`/`in_in_out_result`/`in_out_out_result`/`min_max_result`
Very simple smoke and instantiation tests for the 15 new algorithms in:
* `tests/std/tests/P0896R4_ranges_alg_all_of`
* `tests/std/tests/P0896R4_ranges_alg_any_of`
* `tests/std/tests/P0896R4_ranges_alg_copy`
* `tests/std/tests/P0896R4_ranges_alg_copy_if`
* `tests/std/tests/P0896R4_ranges_alg_copy_n`
* `tests/std/tests/P0896R4_ranges_alg_count`
* `tests/std/tests/P0896R4_ranges_alg_count_if`
* `tests/std/tests/P0896R4_ranges_alg_equal`
* `tests/std/tests/P0896R4_ranges_alg_find`
* `tests/std/tests/P0896R4_ranges_alg_find_if`
* `tests/std/tests/P0896R4_ranges_alg_find_if_not`
* `tests/std/tests/P0896R4_ranges_alg_for_each`
* `tests/std/tests/P0896R4_ranges_alg_for_each_n`
* `tests/std/tests/P0896R4_ranges_alg_mismatch`
* `tests/std/tests/P0896R4_ranges_alg_none_of`
Resolves:
* #537 `<concepts>`: LWG-3175 has been accepted, so we should remove commented-out code
* #540 LWG-3194 `ConvertibleTo` prose does not match code
* #546 LWG-3379 `safe` in several library names is misleading
* #559 P1964R2 "Replacing `boolean` with _`boolean-testable`_"
* #561 P2102R0 "Making 'Implicit Expression Variations' More Explicit"
* #563 P2091R0 "Fixing Issues With Range Access CPOs"
Apply a new attribute '[[msvc::known_semantics]]' to communicate to the compiler that certain type trait specializations have the standard-mandated semantics
* Removes VSO-406237 "C1XX does not do constant initialization where the standard requires" workarounds.
* Introduce `_Immortalize_memcpy_image` which avoids the need for synchronization when constructing the error categories. See the big comment block for explanation of how we got here. For compilers which let us declare instances with the empty virtual destructor as constexpr variables (currently only clang in C++20 mode), we can avoid the workaround.
* Turn on `/Zc:threadSafeInit-` and warning 4640 in most tests to ensure we aren't emitting thread-local initializers in `<system_error>`.
* Move `_Immortalizer` and friends to the one remaining caller in the `exception_ptr` implementation.
* Remove `_Generic_error_category` from the base class hierarchies of error categories to workaround DevCom-928781.
* Reduce the amount of content included by <array>.
Resolves GH-462.
* Demote `back_inserter` and `iterator` to `<iterator>`.
* Demote `_Yarn` to `<xlocinfo>`.
* Demote `_Tidy_guard`, `_Tidy_deallocate_guard`, and `_Nothrow_compare` to `<xmemory>`.
* Promote `_Swap_ranges_unchecked` to `<xutility>`.
* Change `<array>` to include only `<xutility>`.
* Un-demote iterator.
* Workaround many RWC projects that expected std::min and std::max to come from <array>.
* Remove the `_STL_ASSERT` from `std::min` and `std::max`. We normally guard every `op<` with debug checks, but in this case we aren't using it to enforce something like a container invariant; the number of bad op<s we catch with it are likely microscopic.
* Delete `_Min_value` and `_Max_value` from `<utility>`.
* Move `min` and `max` to `<utility>` (in the exact position as the old `_Min_value` and `_Max_value`)
* Change all existing callers of `_Min_value` and `_Max_value` to call `(_STD min)` and `(_STD max)`, respectively.
* Homogenize vector algorithm guards.
Includes:
* concepts `three_way_comparable` and `three_way_comparable_with`,
* type trait `std::compare_three_way_result` (with `_t` alias), and
* function object `compare_three_way`.
in `<compare>`, and:
* function objects `ranges::equal_to` and `ranges::less` (in `<xutility>` for
easy algorithm access), `ranges::not_equal_to`, `ranges::less_equal`,
`ranges::greater`, and `ranges::greater_equal` (in `<functional>`),
* slight refactoring of concept definitions in `<concepts>` to avoid redundant
requirements for the single-type comparison concepts `equality_comparable`,
`totally_ordered`, and `three_way_comparable`,
* heavy refactoring of the trait `common_comparison_category` (and `_t` alias)
in `<compare>` to requires only `n + c` template instantiations instead of `cn`
template instantiations,
* ======== ABI BREAK =========== remove the `_Is_unordered` member from
`std::partial_ordering` in `<compare>` since (a) it's true if and only if the
stored value has a particular value, and (b) Clang expects all of the
comparison category types to have size 1,
* reorder all `is_transparent` alias declarations in the STL to be after the
corresponding `operator()` to agree with synopsis order.
Also adds a new test `P0896R4_P1614R2_comparisons` that exercises the above.
The ABI BREAK sounds scary - as it should - but note that:
* this is a `/std:c++latest` feature, which is subject to change,
* objects of comparison category type aren't typically stored,
* only MSVC has released `<compare>` so far, so it's not widely used.
Altogether, it's extremely unlikely that anyone has encoded this in ABI.
This avoids the allocation in _Winerror_message, and introduces a new version of it which uses FORMAT_MESSAGE_ALLOCATE_BUFFER to completely avoid overallocating memory
Fixes#434
Co-authored-by: Billy O'Neal <billy.oneal@gmail.com>
Co-authored-by: Casey Carter <cartec69@gmail.com>
Deletes stream insertion operators for `ostream` with non-`char` character types, and for `wostream` with `charX_t` character types. The `char8_t` operators are deleted in all language modes, but the others are C++20-only to avoid gratuitous breakage (with escape hatch `_HAS_STREAM_INSERTIONS_REMOVED_IN_CXX20`).
Skips libc++ tests that expect the pre-P1423R3 value of `__cpp_lib_char8_t`.
Resolves#59.
* <span>: fix cross-type iterator operations
* Implement `<=>` for C++20 relational operator rewrites.
* `span<T>::operator-` now accepts `_Span_iterator<U>` when `remove_cv_t<T>` and `remove_cv_t<U>` are the same type.
Drive-by: implement `n + span_iterator` as a hidden friend, and make it `constexpr`.
Fixes#473.
I built clang from the `release/10.x` branch to investigate support for the portions of the STL that require concepts. This went swimmingly, until I was blocked by LLVM-44627 "Reversed candidate operator is not found by argument dependent lookup". These are a few fixes and workarounds I discovered in the process of getting some tests to pass before being blocked completely.
Detailed changes:
`<compare>`:
* Workaround LLVM-41991 "c++2a: attributes on defaulted friend functions incorrectly rejected" by using `_NODISCARD` on such functions only for non-clang.
`<concepts>`:
* Fix typo.
* Workaround LLVM-44689 "[concepts] ICE when *this appears in trailing requires-clause" in `std::ranges::swap`.
`<xhash>`:
* Silence clang warning about template parameter shadowing by renaming.
`<xutility>`:
* Clang thinks my `unreachable_sentinel_t` hack is ill-formed.
This reverts #289 and changes several more algorithms.
Unrelated cleanup: this changes one occurrence of `[[nodiscard]]`
to `_NODISCARD` for consistency.
iso646.h: This suppression is no longer necessary. (Apparently
unrelated to LLVM-43531, fixed after Clang 9.)
xutility: This exceeded 120 columns. clang-format doesn't make it
unreadable, so we should just enable it.
In GH-425 I was forced to add a dead initialization for the _Count variable in _Sort_unchecked in order to comply with constexpr rules. Also, _Sort_unchecked had somewhat complex assignment-in-conditional-expressions going on. This change moves the code around such that the _Count variable is assigned once.
Also:
* Consistently test _ISORT_MAX with <= where possible, and make that an _INLINE_VAR constexpr variable.
* Remove _Count guards of 1 in front of _Insertion_sort_unchecked for consistency. I did performance testing and there was no measurable difference in keeping this check, and it's more code to reason about.
* Avoid needless casts of _ISORT_MAX given that it is now a constexpr constant.
* Implement fixes from D2091R0 "Issues with Range Access CPOs"
* Pre-existing: Correctly annotate implementations of outstanding `iter_move` LWG issues. LWG-3247 was not annotated, and LWG-3299 incorrectly annotated as LWG-3270 (the number had to be changed after submission).
* Remove the `initializer_list` poison pills for `ranges::begin`, `ranges::end`, `ranges::rbegin`, and `ranges::rend`. They were necessary only to prevent `initializer_list` from inadvertently opting-in to forwarding-range, and P1870R1 "forwarding-range<T> is too subtle" changed the opt-in.
* Always perform lookups for lvalues in `ranges::size`, `ranges::empty`, and `ranges::data` as is already the case for `ranges::begin`, `ranges::end`, `ranges::rbegin`, and `ranges::rend` post-P1870, which makes the CPOs easier to reason about and reduces template instantiations.
* Replace forwarding-reference poison pills with pairs of lvalue/const lvalue poison pills for `ranges::begin`, `ranges::end`, `ranges::rbegin`, `ranges::rend`, and `ranges::size`; the forwarding-reference versions are insufficiently poisonous and allow calls to plain `meow(auto&)`/`meow(const auto&)` templates.
* Only perform ADL probes in `ranges::begin`, `ranges::end`, `ranges::rbegin`, `ranges::rend`, and `ranges::size` for argument expressions of class or enumeration type.
* `ranges::begin`, `ranges::empty`, `ranges::data` accept (lvalue) arrays of unknown bound; `ranges::end` (and consequently `ranges::rbegin` and `ranges::rend`) rejects. Remove `range` constraint from `iterator_t`, so it works with (non-`range`) arrays of unknown bound. Add `range` constraints to the `range_meow_t` "compound" associated type traits, since they no longer get it from `iterator_t`.
* Hard error (with a pretty message) in `ranges::begin`, `ranges::end`, `ranges::rbegin`, or `ranges::rend` when the argument is an array whose element type is incomplete.
This bug is triggered when unqualified name lookup for `f` in `f(x)` finds only deleted function (template)s at template definition time, resulting in MSVC refusing to perform argument dependent lookup at template instantiation time. Unsurprisingly, all of the C++20 CPOs required workarounds.
* Implement constexpr algorithms.
Resolves GH-6 ( P0202R3 ), resolves GH-38 ( P0879R0 ), and drive-by fixes GH-414.
Everywhere: Add constexpr, _CONSTEXPR20, and _CONSTEXPR20_ICE to things.
skipped_tests.txt: Turn on all tests previously blocked by missing constexpr algorithms (and exchange and swap). Mark those algorithms that cannot be turned on that we have outstanding PRs for with their associated PRs.
yvals_core.h: Turn on feature test macros.
xutility:
* Move the _Ptr_cat family down to copy, and fix associated SHOUTY comments to indicate that this is really an implementation detail of copy, not something the rest of the standard library intends to use directly. Removed and clarified some of the comments as requested by Casey Carter.
* Extract _Copy_n_core which implements copy_n using only the core language (rather than memcpy-as-an-intrinsic). Note that we cannot use __builtin_memcpy or similar to avoid the is_constant_evaluated check here; builtin_memcpy only works in constexpr contexts when the inputs are of type char.
numeric: Refactor as suggested by GH-414.
* Attempt alternate fix of GH-414 suggested by Stephan.
* Stephan product code PR comments:
* _Swap_ranges_unchecked => _CONSTEXPR20
* _Idl_dist_add => _NODISCARD (and remove comments)
* is_permutation => _NODISCARD
* Add yvals_core.h comments.
* Delete unused _Copy_n_core and TRANSITION, DevCom-889321 comment.
* Put the comments in the right place and remove phantom braces.
* Optimize the is_permutation family and _Hash::operator== for multicontaniers slightly.
<xutility>
4660: _Find_pr is a helper for is_permutation, so move it down to that area.
4684: The SHOUTY banners were attached to functions which were implmentation details of is_permutation, so I fixed them up to say is_permutation and removed the banners for helper functions.
4711: Use if constexpr to avoid a tag dispatch call for _Trim_matching_suffixes. Optimizers will like this because they generally hate reference-to-pointer, and it also serves to workaround DevCom-883631 when this algorithm is constexprized.
4766: Indicate that we are trimming matching prefixes in this loop body, and break apart comment block that was incorrectly merged by clang-format.
4817: In the dual range forward version of the algorithm, calculate the distances concurrently to avoid wasting lots of time when the distances vary by a lot. For example, is_permutation( a forward range of length 1, a forward range of length 1'000'000 ) used to do the million increments, now it stops at 1 increment.
4862: In the dual range random-access version, avoid recalculating _Last2 when it has already been supplied to us.
<xhash>
1404: Move down construction of _Bucket_hi in _Equal_range to before the first loop body using it.
1918: Added a new function to calculate equality for unordered multicontainers. We loop over the elements in the left container, find corresponding ranges in the right container, trim prefixes, then dispatch to is_permutation's helper _Check_match_counts.
Improvements over the old implementation:
* For standard containers, we no longer need to hash any elements from the left container; we know that we've found the "run" of equivalent elements because we *started* with an element in that container. We also never go "backwards" or multiply enumerate _Left (even for !_Standard), which improves cache use when the container becomes large.
* Just like the dual range is_permutation improvement above, when the equal_ranges of the containers are of wildly varying lengths, this will stop on the shorter of the lengths.
* We avoid the 3-arg is_permutation doing a linear time operation to discover _Last2 that we already had calculated in determining _Right's equal_range.
The function _Multi_equal_check_equal_range tests one equal_range from the left container against the corresponding equal_range from the right container, while _Multi_equal invokes _Multi_equal_check_equal_range for each equal_range.
Performance results:
```
Benchmark Before (ns) After (ns) Percent Better
HashRandomUnequal<unordered_multimap>/1 18.7 11.7 59.83%
HashRandomUnequal<unordered_multimap>/10 137 97 41.24%
HashRandomUnequal<unordered_multimap>/100 1677 1141 46.98%
HashRandomUnequal<unordered_multimap>/512 10386 7036 47.61%
HashRandomUnequal<unordered_multimap>/4096 173807 119391 45.58%
HashRandomUnequal<unordered_multimap>/32768 2898405 1529710 89.47%
HashRandomUnequal<unordered_multimap>/100000 27441112 18602792 47.51%
HashRandomUnequal<hash_multimap>/1 18.9 11.8 60.17%
HashRandomUnequal<hash_multimap>/10 138 101 36.63%
HashRandomUnequal<hash_multimap>/100 1613 1154 39.77%
HashRandomUnequal<hash_multimap>/512 10385 7178 44.68%
HashRandomUnequal<hash_multimap>/4096 171718 120115 42.96%
HashRandomUnequal<hash_multimap>/32768 3352231 1510245 121.97%
HashRandomUnequal<hash_multimap>/100000 26532471 19209741 38.12%
HashRandomEqual<unordered_multimap>/1 16 9.4 70.21%
HashRandomEqual<unordered_multimap>/10 126 89.2 41.26%
HashRandomEqual<unordered_multimap>/100 1644 1133 45.10%
HashRandomEqual<unordered_multimap>/512 10532 7183 46.62%
HashRandomEqual<unordered_multimap>/4096 174580 120029 45.45%
HashRandomEqual<unordered_multimap>/32768 3031653 1455416 108.30%
HashRandomEqual<unordered_multimap>/100000 26100504 19240571 35.65%
HashRandomEqual<hash_multimap>/1 15.9 9.38 69.51%
HashRandomEqual<hash_multimap>/10 123 94.1 30.71%
HashRandomEqual<hash_multimap>/100 1645 1151 42.92%
HashRandomEqual<hash_multimap>/512 10177 7144 42.46%
HashRandomEqual<hash_multimap>/4096 172994 121381 42.52%
HashRandomEqual<hash_multimap>/32768 3045242 1966513 54.85%
HashRandomEqual<hash_multimap>/100000 26013781 22025482 18.11%
HashUnequalDifferingBuckets<unordered_multimap>/2 5.87 3.41 72.14%
HashUnequalDifferingBuckets<unordered_multimap>/10 12 3.39 253.98%
HashUnequalDifferingBuckets<unordered_multimap>/100 106 3.41 3008.50%
HashUnequalDifferingBuckets<unordered_multimap>/512 691 3.46 19871.10%
HashUnequalDifferingBuckets<unordered_multimap>/4096 6965 3.47 200620.46%
HashUnequalDifferingBuckets<unordered_multimap>/32768 91451 3.46 2642992.49%
HashUnequalDifferingBuckets<unordered_multimap>/100000 290430 3.52 8250752.27%
HashUnequalDifferingBuckets<hash_multimap>/2 5.97 3.4 75.59%
HashUnequalDifferingBuckets<hash_multimap>/10 11.8 3.54 233.33%
HashUnequalDifferingBuckets<hash_multimap>/100 105 3.54 2866.10%
HashUnequalDifferingBuckets<hash_multimap>/512 763 3.46 21952.02%
HashUnequalDifferingBuckets<hash_multimap>/4096 6862 3.4 201723.53%
HashUnequalDifferingBuckets<hash_multimap>/32768 94583 3.4 2781752.94%
HashUnequalDifferingBuckets<hash_multimap>/100000 287996 3.43 8396284.84%
```
Benchmark code:
```
#undef NDEBUG
#define _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS
#include <assert.h>
#include <benchmark/benchmark.h>
#include <hash_map>
#include <random>
#include <stddef.h>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;
template <template <class...> class MapType> void HashRandomUnequal(benchmark::State &state) {
std::minstd_rand rng(std::random_device{}());
const auto range0 = static_cast<ptrdiff_t>(state.range(0));
vector<pair<unsigned, unsigned>> testData;
testData.resize(range0 * 5);
const auto dataEnd = testData.begin() + range0;
std::generate(testData.begin(), dataEnd, [&]() { return pair<unsigned, unsigned>{rng(), 0u}; });
std::copy(testData.begin(), dataEnd,
std::copy(testData.begin(), dataEnd,
std::copy(testData.begin(), dataEnd, std::copy(testData.begin(), dataEnd, dataEnd))));
std::unordered_multimap<unsigned, unsigned> a(testData.begin(), testData.end());
testData.clear();
std::unordered_multimap<unsigned, unsigned> b = a;
next(b.begin(), b.size() - 1)->second = 1u;
for (auto &&_ : state) {
(void)_;
assert(a != b);
}
}
BENCHMARK_TEMPLATE1(HashRandomUnequal, unordered_multimap)->Arg(1)->Arg(10)->Range(100, 100'000);
BENCHMARK_TEMPLATE1(HashRandomUnequal, hash_multimap)->Arg(1)->Arg(10)->Range(100, 100'000);
template <template <class...> class MapType> void HashRandomEqual(benchmark::State &state) {
std::minstd_rand rng(std::random_device{}());
const auto range0 = static_cast<ptrdiff_t>(state.range(0));
vector<pair<unsigned, unsigned>> testData;
testData.resize(range0 * 5);
const auto dataEnd = testData.begin() + range0;
std::generate(testData.begin(), dataEnd, [&]() { return pair<unsigned, unsigned>{rng(), 0}; });
std::copy(testData.begin(), dataEnd,
std::copy(testData.begin(), dataEnd,
std::copy(testData.begin(), dataEnd, std::copy(testData.begin(), dataEnd, dataEnd))));
std::unordered_multimap<unsigned, unsigned> a(testData.begin(), testData.end());
testData.clear();
std::unordered_multimap<unsigned, unsigned> b = a;
for (auto &&_ : state) {
(void)_;
assert(a == b);
}
}
BENCHMARK_TEMPLATE1(HashRandomEqual, unordered_multimap)->Arg(1)->Arg(10)->Range(100, 100'000);
BENCHMARK_TEMPLATE1(HashRandomEqual, hash_multimap)->Arg(1)->Arg(10)->Range(100, 100'000);
template <template <class...> class MapType> void HashUnequalDifferingBuckets(benchmark::State &state) {
std::unordered_multimap<unsigned, unsigned> a;
std::unordered_multimap<unsigned, unsigned> b;
const auto range0 = static_cast<ptrdiff_t>(state.range(0));
for (ptrdiff_t idx = 0; idx < range0; ++idx) {
a.emplace(0, 1);
b.emplace(1, 0);
}
a.emplace(1, 0);
b.emplace(0, 1);
for (auto &&_ : state) {
(void)_;
assert(a != b);
}
}
BENCHMARK_TEMPLATE1(HashUnequalDifferingBuckets, unordered_multimap)->Arg(2)->Arg(10)->Range(100, 100'000);
BENCHMARK_TEMPLATE1(HashUnequalDifferingBuckets, hash_multimap)->Arg(2)->Arg(10)->Range(100, 100'000);
BENCHMARK_MAIN();
* Apply a bunch of code review comments from Casey.
* clang-format
* Apply @miscco's code deduplication idea for <xhash>.
* Fix code review comments from Stephan: comments and add DMIs.
This change is not a statement of support for the Intel C++ compiler by the STL, so much as an attempt to not break it gratuitously.
Fixes DevCom-744112.
* Implement P0357R3
* Update LLVM to get skip of libcxx\test\std\utilities\function.objects\refwrap\weak_result.pass.cpp, and exclude "// REQUIRES: c++98 || c++03 || c++11 || c++14 || c++17" as a 'magic comment'.
Co-authored-by: Billy O'Neal <billy.oneal@gmail.com>
Co-authored-by: Casey Carter <cartec69@gmail.com>
...which renames the feature-test macro `__cpp_lib_nothrow_convertible` to `__cpp_lib_is_nothrow_convertible`. We *just* added this feature-test macro which hasn't yet shipped, and therefore want to rename it quickly - ideally before customers notice it exists. LWG has tentatively approved this issue resolution.
This calls `abort()` as there's no need to invoke the terminate handler.
(This is a virtual function, so eliminating it entirely would risk ODR
violations leading to crashes. It's much safer to provide a definition
that can't be called.)
Additionally, fix `<xlocale>` to qualify `_CSTD abort()`.
While we must continue to support `msvcp140.dll` running on Windows XP,
we don't need to support compiling our headers with the (removed)
`v140_xp` toolset and its corresponding old Windows SDK. Accordingly,
we can unconditionally define `shared_mutex`. (This is a C++17 feature,
but it was implemented before Standard modes, so it's not guarded by
`_HAS_CXX17`.)
Currently, we're building the STL in both our Microsoft-internal MSVC
repo and in GitHub, as we work on the migration. The MSVC repo uses a
checked-in compiler (the "toolset") to build the STL and the compiler
itself. Earlier, the checked-in toolset identified itself as
19.25.28318.97 but lacked support for `is_constant_evaluated`, so we
needed to detect that exact version number. Now, the toolset has been
updated, so this workaround is no longer necessary.
When VS 2019 16.5 Preview 2 is available in the future, we'll begin
requiring it to build the GitHub sources, at which point we'll be able
to unconditionally define `__cpp_lib_is_constant_evaluated`.
* Avoid burning unused stack space for a T in _List_node_insert_op. Resolves#973579 and GH-365.
* Change forward_list to follow a similar pattern for consistency.
* First round of code review feedback.
Permanently work around DevCom-848104 by simplifying hash_meow::value_type. This is what unordered_meow::value_type already does, which is why that can already use int = 0 SFINAE.
* Fix#272: `<future>: promise<_Ty&>::set_value(_Ty& _Val)` should use `_STD addressof(_Val)`
* Fix#344: `<yvals_core.h>`: Update `_MSVC_STL_UPDATE` to December 2019
Hidden friends aren't hidden in C1XX's permissive mode, so let's use an alternate mechanism to make these operators truly ADL-only. (We want to avoid checking `weakly_incrementable` for every type that is compared via `==` or `!=` with a type associated with namespace `std`.)
Programs that include such specializations are ill-formed, since the Standard only specifies a partial specialization of `std::function<T>` for non-`noexcept` function types `T`. The current diagnostic:
```
error C2027: use of undefined type 'std::_Get_function_impl<_Fty>'
```
is not great.
Fixes DevCom-825902.
[This is a replay of Microsoft-internal MSVC-PR-215822.]
Implements iterator primitive operations `std::ranges::advance`, `std::ranges::next`, `std::ranges::prev`, and `std::ranges::distance`; as well as `std::default_sentinel` and `std::unreachable_sentinel`.
This change reworks the STL's iterator unwrapping machinery to enable unwrapping of C++20 move-only single-pass iterators (and `if constepxr`s all the things). Consequently, `_Iter_ref_t`, `_Iter_value_t`, and `_Iter_diff_t` resolve to `iter_reference_t`, `iter_value_t`, and `iter_difference_t` (respectively) in `__cpp_lib_concepts` (soon to be C++20) mode. This change necessitates some fixes to `unique_copy` and `_Fill_memset_is_safe` which both assume that `_Iter_value_t<T>` is well-formed for any iterator `T`. (`iter_value_t<T>` does not have that property: it is only well-formed when `readable<T>`.)
I notably haven't unified `default_sentinel_t` with `_Default_sentinel` out of an abundance of paranoia. Our `move_iterator` is comparable with `_Default_sentinel`, which is not the case for `std::default_sentinel`.
Drive-by:
* This change `if constexpr`-izes `unique_copy`.
This feature-test macro is being extensively queried, so we're updating it with high priority ahead of the other feature-test macro changes in this paper.
* Use unqualified function calls for valarray
The transcend functions require that the function is applied unqualified to each element
* Add comments to unqualified calls.
Fixes#285.
Krystyna Lopez
Casey Carter
Casey Carter
Billy O'Neal
Stephan T. Lavavej
Michael Schellenberger Costa
Adam Bucior
Charlie Barto
Jean Philippe
Xiang Fan
mocabe
Svido
Daniel Marshall
Charles Milette
statementreply
Pavol Misik
Daniil Goncharov
Michael Schellenberger Costa
Nikita Kniazev
Julie Philip James
SasLuca
S. B. Tam
