* Update to Clang 10 and Visual Studio 2019 version 16.6p2
* re-clang-formats the tree to comply with new clang 10 clang-format
* updates our agents to F series VMs which are faster and cheaper for our build workloads
* defaults scale set to 0 VMs and lets the Azure Pipelines service control all resizing
* fix tests to pass with the new compilers
Co-authored by Casey Carter and Curtis Bezault
Apply a new attribute '[[msvc::known_semantics]]' to communicate to the compiler that certain type trait specializations have the standard-mandated semantics
* 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.
* 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.
Fixes#187.
Add TRANSITION comments for #248 and #249, blocked by compiler bugs.
Add `_Enabled` names. When we don't have `enable_if_t`, this makes the
template parameter's purpose clearer. When we do have `enable_if_t`
but without `= 0`, this makes it somewhat clearer that we haven't
forgotten the default argument (it's simply elsewhere).
* Properly comment "Tukey's ninther".
* Remove workarounds for VSO-946746.
VSO-946746 "conditional explicit(bool) doesn't work with /clr:pure"
was fixed on 2019-07-23, and should be available in
VS 2019 16.4 Preview 1.
* Remove workarounds for VSO-433486.
VSO-433486 "_Count / 2 inside while (0 < _Count) loop is not
transformed into a simple shift" was fixed on 2019-08-27
and should be available in VS 2019 16.4 Preview 2.
Some shifts are still necessary, and are now commented.
* This mirrors a Microsoft-internal PR:
https://devdiv.visualstudio.com/DevDiv/_git/msvc/pullrequest/207988
Billy O'Neal
Michael Schellenberger Costa
Xiang Fan
Adam Bucior
Daniel Marshall
Krystyna Lopez
Stephan T. Lavavej