Toolset update: VS 2019 16.10 Preview 4

README.md

@@ -143,7 +143,7 @@ Just try to follow these rules, so we can spend more time fixing bugs and implem
 The STL uses boost-math headers to provide P0226R1 Mathematical Special Functions. We recommend using [vcpkg][] to
 acquire this dependency.
 
-1. Install Visual Studio 2019 16.10 Preview 2 or later.
+1. Install Visual Studio 2019 16.10 Preview 4 or later.
     * We recommend selecting "C++ CMake tools for Windows" in the VS Installer.
     This will ensure that you're using supported versions of CMake and Ninja.
     * Otherwise, install [CMake][] 3.20 or later, and [Ninja][] 1.10.2 or later.
@@ -158,7 +158,7 @@ acquire this dependency.
 
 # How To Build With A Native Tools Command Prompt
 
-1. Install Visual Studio 2019 16.10 Preview 2 or later.
+1. Install Visual Studio 2019 16.10 Preview 4 or later.
     * We recommend selecting "C++ CMake tools for Windows" in the VS Installer.
     This will ensure that you're using supported versions of CMake and Ninja.
     * Otherwise, install [CMake][] 3.20 or later, and [Ninja][] 1.10.2 or later.
@@ -234,7 +234,7 @@ C:\Users\username\Desktop>dumpbin /IMPORTS .\example.exe | findstr msvcp
 # How To Run The Tests With A Native Tools Command Prompt
 
 1. Follow either [How To Build With A Native Tools Command Prompt][] or [How To Build With The Visual Studio IDE][].
-2. Acquire [Python][] 3.9.4 or newer and have it on the `PATH` (or run it directly using its absolute or relative path).
+2. Acquire [Python][] 3.9.5 or newer and have it on the `PATH` (or run it directly using its absolute or relative path).
 3. Have LLVM's `bin` directory on the `PATH` (so `clang-cl.exe` is available).
     * We recommend selecting "C++ Clang tools for Windows" in the VS Installer. This will automatically add LLVM to the
     `PATH` of the x86 and x64 Native Tools Command Prompts, and will ensure that you're using a supported version.

azure-devops/create-vmss.ps1

@@ -30,7 +30,7 @@ $ImageOffer = 'Windows-10'
 $ImageSku = '20h2-ent-g2'
 
 $ProgressActivity = 'Creating Scale Set'
-$TotalProgress = 13
+$TotalProgress = 14
 $CurrentProgress = 1
 
 <#
@@ -304,6 +304,14 @@ Write-Progress `
 
 Restart-AzVM -ResourceGroupName $ResourceGroupName -Name $ProtoVMName
 
+####################################################################################################
+Write-Progress `
+  -Activity $ProgressActivity `
+  -Status 'Sleeping after restart' `
+  -PercentComplete (100 / $TotalProgress * $CurrentProgress++)
+
+Start-Sleep -Seconds 60
+
 ####################################################################################################
 Write-Progress `
   -Activity $ProgressActivity `

azure-devops/provision-image.ps1

@@ -139,7 +139,7 @@ $Workloads = @(
 $ReleaseInPath = 'Preview'
 $Sku = 'Enterprise'
 $VisualStudioBootstrapperUrl = 'https://aka.ms/vs/16/pre/vs_enterprise.exe'
-$PythonUrl = 'https://www.python.org/ftp/python/3.9.4/python-3.9.4-amd64.exe'
+$PythonUrl = 'https://www.python.org/ftp/python/3.9.5/python-3.9.5-amd64.exe'
 
 # https://docs.microsoft.com/en-us/windows-hardware/drivers/download-the-wdk
 $WindowsDriverKitUrl = 'https://go.microsoft.com/fwlink/?linkid=2128854'

azure-pipelines.yml

@@ -8,7 +8,7 @@ variables:
   buildOutputLocation: 'D:\build'
   vcpkgLocation: '$(Build.SourcesDirectory)/vcpkg'
 
-pool: 'StlBuild-2021-04-23'
+pool: 'StlBuild-2021-05-18'
 
 stages:
   - stage: Code_Format

stl/inc/chrono

@@ -2977,8 +2977,8 @@ namespace chrono {
         explicit zoned_time(_TimeZonePtr _Tz) noexcept /* strengthened */ : _Zone{_STD move(_Tz)} {}
 
         // clang-format off
-        template <class _Traits2 = _Traits, enable_if_t<is_constructible< // TRANSITION, VSO-1303556
-            zoned_time, decltype(_Traits2::locate_zone(string_view{}))>::value,
+        template <class _Traits2 = _Traits, enable_if_t<is_constructible_v<
+            zoned_time, decltype(_Traits2::locate_zone(string_view{}))>,
             int> = 0>
         // clang-format on
         explicit zoned_time(string_view _Name) : _Zone{_Traits::locate_zone(_Name)} {}
@@ -2990,8 +2990,8 @@ namespace chrono {
         zoned_time(_TimeZonePtr _Tz, const sys_time<_Duration>& _Sys) : _Zone{_STD move(_Tz)}, _Tp{_Sys} {}
 
         // clang-format off
-        template <class _Traits2 = _Traits, enable_if_t<is_constructible< // TRANSITION, VSO-1303556
-            zoned_time, decltype(_Traits2::locate_zone(string_view{})), const sys_time<_Duration>&>::value,
+        template <class _Traits2 = _Traits, enable_if_t<is_constructible_v<
+            zoned_time, decltype(_Traits2::locate_zone(string_view{})), const sys_time<_Duration>&>,
             int> = 0>
         // clang-format on
         zoned_time(string_view _Name, type_identity_t<const sys_time<_Duration>&> _Sys)
@@ -3005,8 +3005,8 @@ namespace chrono {
             : _Zone{_STD move(_Tz)}, _Tp{_Zone->to_sys(_Local)} {}
 
         // clang-format off
-        template <class _Traits2 = _Traits, enable_if_t<is_constructible< // TRANSITION, VSO-1303556
-            zoned_time, decltype(_Traits2::locate_zone(string_view{})), const local_time<_Duration>&>::value,
+        template <class _Traits2 = _Traits, enable_if_t<is_constructible_v<
+            zoned_time, decltype(_Traits2::locate_zone(string_view{})), const local_time<_Duration>&>,
             int> = 0>
         // clang-format on
         zoned_time(string_view _Name, type_identity_t<const local_time<_Duration>>& _Local)
@@ -3021,8 +3021,8 @@ namespace chrono {
             : _Zone{_STD move(_Tz)}, _Tp{_Zone->to_sys(_Local, _Choose)} {}
 
         // clang-format off
-        template <class _Traits2 = _Traits, enable_if_t<is_constructible< // TRANSITION, VSO-1303556
-            zoned_time, decltype(_Traits2::locate_zone(string_view{})), const local_time<_Duration>&, choose>::value,
+        template <class _Traits2 = _Traits, enable_if_t<is_constructible_v<
+            zoned_time, decltype(_Traits2::locate_zone(string_view{})), const local_time<_Duration>&, choose>,
             int> = 0>
         // clang-format on
         zoned_time(string_view _Name, type_identity_t<const local_time<_Duration>&> _Local, choose _Choose)
@@ -3041,19 +3041,19 @@ namespace chrono {
 
         // clang-format off
         template <class _Duration2, class _TimeZonePtr2,
-            class _Traits2 = _Traits, enable_if_t<is_constructible< // TRANSITION, VSO-1303556
+            class _Traits2 = _Traits, enable_if_t<is_constructible_v<
             zoned_time, decltype(_Traits2::locate_zone(string_view{})),
-            const zoned_time<_Duration2, _TimeZonePtr2>&>::value,
+            const zoned_time<_Duration2, _TimeZonePtr2>&>,
             int> = 0>
         // clang-format on
         zoned_time(string_view _Name, const zoned_time<_Duration2, _TimeZonePtr2>& _Zt)
             : zoned_time{_Traits::locate_zone(_Name), _Zt} {}
 
         // clang-format off
         template <class _Duration2, class _TimeZonePtr2,
-            class _Traits2 = _Traits, enable_if_t<is_constructible< // TRANSITION, VSO-1303556
+            class _Traits2 = _Traits, enable_if_t<is_constructible_v<
             zoned_time, decltype(_Traits2::locate_zone(string_view{})),
-            const zoned_time<_Duration2, _TimeZonePtr2>&, choose>::value,
+            const zoned_time<_Duration2, _TimeZonePtr2>&, choose>,
             int> = 0>
         // clang-format on
         zoned_time(string_view _Name, const zoned_time<_Duration2, _TimeZonePtr2>& _Zt, choose _Choose)

stl/inc/execution

@@ -446,7 +446,7 @@ struct _Parallel_choose_min_chunk {
             }
         }
 
-        lock_guard<mutex> _Lck(_Mtx); // TRANSITION, VSO-671180
+        lock_guard _Lck(_Mtx);
         if (_Selected_chunk.load(memory_order_relaxed) == _Chunk) {
             _Result = _Local_result;
         }
@@ -481,7 +481,7 @@ struct _Parallel_choose_max_chunk {
             }
         }
 
-        lock_guard<mutex> _Lck(_Mtx); // TRANSITION, VSO-671180
+        lock_guard _Lck(_Mtx);
         if (_Selected_chunk.load(memory_order_relaxed) == _Chunk) {
             _Result = _Local_result;
         }
@@ -589,7 +589,7 @@ public:
             auto _New_segment = _Segment->_Grow(_Local_b, _Local_t);
             _Circular_buffer<_Ty>* _Detached_segment;
             {
-                lock_guard<mutex> _Lck(_Segment_lock); // TRANSITION, VSO-671180
+                lock_guard _Lck(_Segment_lock);
                 _Detached_segment = _STD exchange(_Segment, _New_segment);
             } // unlock
 
@@ -614,7 +614,7 @@ public:
 
             _Circular_buffer<_Ty>* _Stealing_segment;
             {
-                lock_guard<mutex> _Lck(_Segment_lock); // TRANSITION, VSO-671180
+                lock_guard _Lck(_Segment_lock);
                 _Stealing_segment = _Segment;
                 _MT_INCR(_Stealing_segment->_Ref_count);
             }
@@ -750,7 +750,7 @@ struct _Work_stealing_team { // inter-thread communication for threads working o
     _Work_stealing_membership<_Ty> _Join_team() noexcept {
         size_t _Id;
         {
-            lock_guard<mutex> _Lck(_Available_mutex); // TRANSITION, VSO-671180
+            lock_guard _Lck(_Available_mutex);
             _Id = _Available_queues.top();
             _Available_queues.pop();
         } // unlock
@@ -764,7 +764,7 @@ struct _Work_stealing_team { // inter-thread communication for threads working o
     }
 
     void _Leave_team(size_t _Id) noexcept {
-        lock_guard<mutex> _Lck(_Available_mutex); // TRANSITION, VSO-671180
+        lock_guard _Lck(_Available_mutex);
         _Available_queues.push(_Id);
     }
 

stl/inc/queue

@@ -108,7 +108,7 @@ public:
         _Swap_adl(c, _Right.c);
     }
 
-    _NODISCARD const _Container& _Get_container() const noexcept { // TRANSITION, VSO-1307828
+    _NODISCARD const _Container& _Get_container() const noexcept {
         return c;
     }
 

stl/inc/stack

@@ -98,7 +98,7 @@ public:
         _Swap_adl(c, _Right.c);
     }
 
-    _NODISCARD const _Container& _Get_container() const noexcept { // TRANSITION, VSO-1307828
+    _NODISCARD const _Container& _Get_container() const noexcept {
         return c;
     }
 

stl/inc/tuple

@@ -683,10 +683,10 @@ public:
     }
 
 #ifdef __cpp_lib_concepts
-    template <class _First, class... _Other,
-        class _Ret = common_comparison_category_t<_Synth_three_way_result<_This, _First>, // TRANSITION, DevCom-1344701
-            _Synth_three_way_result<_Rest, _Other>...>> // (should be a normal or trailing return type)
-    _NODISCARD constexpr _Ret _Three_way_compare(const tuple<_First, _Other...>& _Right) const {
+    template <class _First, class... _Other>
+    _NODISCARD constexpr common_comparison_category_t<_Synth_three_way_result<_This, _First>,
+        _Synth_three_way_result<_Rest, _Other>...>
+        _Three_way_compare(const tuple<_First, _Other...>& _Right) const {
         if (auto _Result = _Synth_three_way{}(_Myfirst._Val, _Right._Myfirst._Val); _Result != 0) {
             return _Result;
         }

stl/inc/type_traits

@@ -1364,11 +1364,7 @@ template <class _Ty1, class _Ty2, class = void>
 struct _Common_reference2A : _Common_reference2B<_Ty1, _Ty2> {};
 
 template <class _Ty1, class _Ty2, class _Result = _Cond_res<_Copy_cv<_Ty1, _Ty2>&, _Copy_cv<_Ty2, _Ty1>&>,
-#ifdef __EDG__ // TRANSITION, VSO-948614
-    enable_if_t<is_lvalue_reference<_Result>::value, int> = 0>
-#else // ^^^ workaround / no workaround vvv
     enable_if_t<is_lvalue_reference_v<_Result>, int> = 0>
-#endif // TRANSITION, VSO-948614
 using _LL_common_ref = _Result;
 
 template <class _Ty1, class _Ty2>

stl/inc/variant

@@ -1173,18 +1173,11 @@ public:
         } else if constexpr (sizeof...(_Types) < 32) {
             // Limit the size of variants that use this quadratic code size implementation of swap.
             _Variant_raw_visit(index(), _Storage(),
-                [this, &_That](auto _My_ref)
-#ifndef __EDG__ // TRANSITION, VSO-897887
-                    noexcept(conjunction_v<is_nothrow_move_constructible<_Types>..., is_nothrow_swappable<_Types>...>)
-#endif // TRANSITION, VSO-897887
-                {
+                [this, &_That](auto _My_ref) noexcept(
+                    conjunction_v<is_nothrow_move_constructible<_Types>..., is_nothrow_swappable<_Types>...>) {
                     _Variant_raw_visit(_That.index(), _That._Storage(),
-                        [this, &_That, _My_ref](auto _That_ref)
-#ifndef __EDG__ // TRANSITION, VSO-897887
-                            noexcept(conjunction_v<is_nothrow_move_constructible<_Types>...,
-                                is_nothrow_swappable<_Types>...>)
-#endif // TRANSITION, VSO-897887
-                        {
+                        [this, &_That, _My_ref](auto _That_ref) noexcept(
+                            conjunction_v<is_nothrow_move_constructible<_Types>..., is_nothrow_swappable<_Types>...>) {
                             constexpr size_t _That_idx = decltype(_That_ref)::_Idx;
 #ifdef __EDG__ // TRANSITION, VSO-657455
                             constexpr size_t _My_idx = decltype(_My_ref)::_Idx + 0 * _That_idx;
@@ -1218,11 +1211,7 @@ public:
         } else {
             if (this->_Which == _That._Which) {
                 _Variant_raw_visit(static_cast<size_t>(this->_Which), _That._Storage(),
-                    [this](auto _Ref)
-#ifndef __EDG__ // TRANSITION, VSO-897887
-                        noexcept(conjunction_v<is_nothrow_swappable<_Types>...>)
-#endif // TRANSITION, VSO-897887
-                    {
+                    [this](auto _Ref) noexcept(conjunction_v<is_nothrow_swappable<_Types>...>) {
                         constexpr size_t _Idx = decltype(_Ref)::_Idx;
                         if constexpr (_Idx != variant_npos) {
                             _Swap_adl(_Variant_raw_get<_Idx>(this->_Storage()), _Ref._Val);
@@ -1255,11 +1244,7 @@ private:
         // steal the contained value from _That
         this->_Reset();
         _Variant_raw_visit(_That.index(), _That._Storage(),
-            [this](auto _Ref)
-#ifndef __EDG__ // TRANSITION, VSO-897887
-                noexcept(conjunction_v<is_nothrow_move_constructible<_Types>...>)
-#endif // TRANSITION, VSO-897887
-            {
+            [this](auto _Ref) noexcept(conjunction_v<is_nothrow_move_constructible<_Types>...>) {
                 constexpr size_t _Idx = decltype(_Ref)::_Idx;
                 if constexpr (_Idx != variant_npos) {
                     this->_Emplace_valueless<_Idx>(_STD move(_Ref._Val));

tests/libcxx/expected_results.txt

@@ -432,9 +432,6 @@ std/numerics/c.math/cmath.pass.cpp FAIL
 # GH-1596: <algorithm>: unqualified calls to _Adl_verify_range incorrectly cause instantiation
 std/algorithms/robust_against_adl.pass.cpp FAIL
 
-# GH-1595: <bit>: bit_ceil(T(-1)) should not be a constant expression
-std/numerics/bit/bit.pow.two/bit_ceil.fail.cpp:0 FAIL
-
 
 # *** CRT BUGS ***
 # We're permanently missing aligned_alloc().

tests/libcxx/skipped_tests.txt

@@ -432,9 +432,6 @@ numerics\c.math\cmath.pass.cpp
 # GH-1596: <algorithm>: unqualified calls to _Adl_verify_range incorrectly cause instantiation
 algorithms\robust_against_adl.pass.cpp
 
-# GH-1595: <bit>: bit_ceil(T(-1)) should not be a constant expression
-numerics\bit\bit.pow.two\bit_ceil.fail.cpp
-
 
 # *** CRT BUGS ***
 # We're permanently missing aligned_alloc().

tests/std/tests/Dev11_0535636_functional_overhaul/test.cpp

@@ -980,11 +980,9 @@ void test_reference_wrapper_invocation() {
 
     assert(i == 10);
 
-#ifndef __EDG__ // TRANSITION, DevCom-939485
     const auto noexcept_lambda     = []() noexcept {};
     const auto noexcept_lambda_ref = ref(noexcept_lambda);
     STATIC_ASSERT(noexcept(noexcept_lambda_ref())); // strengthened
-#endif // __EDG__
 
     reference_wrapper<int(int)> rw_fxn(quadruple);
     assert(rw_fxn(9) == 36);
@@ -1055,12 +1053,18 @@ constexpr bool test_invoke_constexpr() {
     auto p = &thing;
 
     assert(&invoke(&Thing::m_x, *p) == &p->m_x);
-    // assert(&invoke(&Thing::m_x, ref(*sp)) == &sp->m_x); TRANSITION, P1065R2
+#if _HAS_CXX20
+#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-1419425 "constexpr PMD emits bogus error C2131"
+    assert(&invoke(&Thing::m_x, ref(*p)) == &p->m_x);
+#endif // ^^^ no workaround ^^^
+#endif // _HAS_CXX20
     assert(&invoke(&Thing::m_x, p) == &p->m_x);
 
 #ifndef _M_CEE // TRANSITION, DevCom-939490
     assert(invoke(&Thing::sum, *p, 3) == 1023);
-    // assert(invoke(&Thing::sum, ref(*sp), 4) == 1024); TRANSITION, P1065R2
+#if _HAS_CXX20
+    assert(invoke(&Thing::sum, ref(*p), 4) == 1024);
+#endif // _HAS_CXX20
     assert(invoke(&Thing::sum, p, 5) == 1025);
 #endif // _M_CEE
 

tests/std/tests/P0067R5_charconv/float_to_chars_test_cases.hpp

@@ -140,7 +140,7 @@ inline constexpr FloatToCharsTestCase float_to_chars_test_cases[] = {
     {6.0898e-39f, chars_format::scientific, "6.0898e-39"},
     {0.0010310042f, chars_format::scientific, "1.0310042e-03"},
     {2.8823261e17f, chars_format::scientific, "2.882326e+17"},
-    {0x1.5c87fap-84f, chars_format::scientific, "7.038531e-26"}, // TRANSITION, VSO-629490, should be 7.038531e-26f
+    {7.038531e-26f, chars_format::scientific, "7.038531e-26"},
     {9.2234038e17f, chars_format::scientific, "9.223404e+17"},
     {6.7108872e7f, chars_format::scientific, "6.710887e+07"},
     {1.0e-44f, chars_format::scientific, "1e-44"},