Merge pull request #1212 from microsoft/master

feature/spaceship: Merge fix for test timing assumption

stl/inc/algorithm

@@ -5118,7 +5118,9 @@ namespace ranges {
 
                     return {_STD move(_First), _STD move(_Final)};
                 } else {
-                    auto [_Mid_first, _Mid_last] = _Reverse_until_mid_unchecked(_STD move(_First), _Mid, _Final);
+                    const auto _Result = _Reverse_until_mid_unchecked(_STD move(_First), _Mid, _Final);
+                    auto _Mid_first    = _Result.begin();
+                    auto _Mid_last     = _Result.end();
                     _Reverse_common(_Mid_first, _Mid_last);
 
                     if (_Mid_first == _Mid) {

stl/inc/any

@@ -58,7 +58,7 @@ inline constexpr bool _Any_is_small = alignof(_Ty) <= alignof(max_align_t)
 enum class _Any_representation : uintptr_t { _Trivial, _Big, _Small };
 
 struct _Any_big_RTTI { // Hand-rolled vtable for types that must be heap allocated in an any
-    using _Destroy_fn = void __CLRCALL_PURE_OR_CDECL(void*) noexcept;
+    using _Destroy_fn = void __CLRCALL_PURE_OR_CDECL(void*) _NOEXCEPT_FNPTR;
     using _Copy_fn    = void* __CLRCALL_PURE_OR_CDECL(const void*);
 
     template <class _Ty>
@@ -76,9 +76,9 @@ struct _Any_big_RTTI { // Hand-rolled vtable for types that must be heap allocat
 };
 
 struct _Any_small_RTTI { // Hand-rolled vtable for nontrivial types that can be stored internally in an any
-    using _Destroy_fn = void __CLRCALL_PURE_OR_CDECL(void*) noexcept;
+    using _Destroy_fn = void __CLRCALL_PURE_OR_CDECL(void*) _NOEXCEPT_FNPTR;
     using _Copy_fn    = void __CLRCALL_PURE_OR_CDECL(void*, const void*);
-    using _Move_fn    = void __CLRCALL_PURE_OR_CDECL(void*, void*) noexcept;
+    using _Move_fn    = void __CLRCALL_PURE_OR_CDECL(void*, void*) _NOEXCEPT_FNPTR;
 
     template <class _Ty>
     static void __CLRCALL_PURE_OR_CDECL _Destroy_impl(void* const _Target) noexcept {

stl/inc/charconv

@@ -1327,9 +1327,11 @@ _NODISCARD errc _Assemble_floating_point_value(const uint64_t _Initial_mantissa,
 
             // We detect this case here and re-adjust the mantissa and exponent appropriately, to form a normal number:
             if (_Mantissa > _Traits::_Denormal_mantissa_mask) {
-                // We add one to the _Denormal_mantissa_shift to account for the hidden mantissa bit
-                // (we subtracted one to account for this bit when we computed the _Denormal_mantissa_shift above).
-                _Exponent = _Initial_exponent - (_Denormal_mantissa_shift + 1) - _Normal_mantissa_shift;
+                // The mantissa is already in the correct position for a normal value. (The carried over bit when we
+                // added 1 to round the mantissa is in the correct position for the hidden bit.)
+                // _Denormal_mantissa_shift is the actual number of bits by which we have shifted the mantissa into its
+                // final position.
+                _Exponent = _Initial_exponent - _Denormal_mantissa_shift;
             }
         } else {
             _Mantissa <<= _Denormal_mantissa_shift;

stl/inc/iterator

@@ -511,6 +511,311 @@ private:
     bool _Failed; // true if any stores have failed
     streambuf_type* _Strbuf; // the wrapped stream buffer
 };
+
+#ifdef __cpp_lib_concepts
+// CLASS TEMPLATE counted_iterator
+template <input_or_output_iterator _Iter>
+class counted_iterator {
+public:
+    using iterator_type = _Iter;
+
+    // [counted.iter.const]
+    constexpr counted_iterator() = default;
+    constexpr counted_iterator(_Iter _Right, const iter_difference_t<_Iter> _Diff) noexcept(
+        is_nothrow_move_constructible_v<_Iter>) // strengthened
+        : _Current(_STD move(_Right)), _Length(_Diff) {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _STL_VERIFY(_Diff >= 0, "counted_iterator requires non-negative length n");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+    }
+
+    // clang-format off
+    template <class _Other>
+        requires convertible_to<const _Other&, _Iter>
+    constexpr counted_iterator(const counted_iterator<_Other>& _Right) noexcept(
+        is_nothrow_constructible_v<_Iter, const _Other&>) // strengthened
+        : _Current(_Right._Current), _Length(_Right._Length) {}
+
+    template <class _Other>
+        requires assignable_from<_Iter&, const _Other&>
+    constexpr counted_iterator& operator=(const counted_iterator<_Other>& _Right) noexcept(
+        is_nothrow_assignable_v<_Iter&, const _Other&>) /* strengthened */ {
+        // clang-format on
+        _Current = _Right._Current;
+        _Length  = _Right._Length;
+        return *this;
+    }
+
+    // [counted.iter.access]
+    _NODISCARD constexpr _Iter base() const& noexcept(is_nothrow_copy_constructible_v<_Iter>) /* strengthened */
+        requires copy_constructible<_Iter> {
+        return _Current;
+    }
+
+    _NODISCARD constexpr _Iter base() && noexcept(is_nothrow_move_constructible_v<_Iter>) /* strengthened */ {
+        return _STD move(_Current);
+    }
+
+    _NODISCARD constexpr iter_difference_t<_Iter> count() const noexcept {
+        return _Length;
+    }
+
+    // [counted.iter.elem]
+    _NODISCARD constexpr decltype(auto) operator*() noexcept(noexcept(*_Current)) /* strengthened */ {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        // Per proposed resolution of LWG-3472
+        _STL_VERIFY(_Length > 0, "counted_iterator dereference beyond end of range");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        return *_Current;
+    }
+
+    _NODISCARD constexpr decltype(auto) operator*() const noexcept(noexcept(*_Current)) /* strengthened */
+        requires _Dereferenceable<const _Iter> {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        // Per proposed resolution of LWG-3472
+        _STL_VERIFY(_Length > 0, "counted_iterator dereference beyond end of range");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        return *_Current;
+    }
+
+    _NODISCARD constexpr decltype(auto) operator[](const iter_difference_t<_Iter> _Diff) const
+        requires random_access_iterator<_Iter> {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _STL_VERIFY(_Diff < _Length, "counted_iterator index out of range");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        return _Current[_Diff];
+    }
+
+    // [counted.iter.nav]
+    constexpr counted_iterator& operator++() {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _STL_VERIFY(_Length > 0, "counted_iterator increment beyond end of range");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        ++_Current;
+        --_Length;
+        return *this;
+    }
+
+    constexpr decltype(auto) operator++(int) {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _STL_VERIFY(_Length > 0, "counted_iterator increment beyond end of range");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        --_Length;
+        _TRY_BEGIN
+        return _Current++;
+
+        _CATCH_ALL
+        ++_Length;
+
+        _RERAISE;
+        _CATCH_END
+    }
+
+    constexpr counted_iterator operator++(int) requires forward_iterator<_Iter> {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _STL_VERIFY(_Length > 0, "counted_iterator increment beyond end of range");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        counted_iterator _Tmp = *this;
+        ++_Current;
+        --_Length;
+        return _Tmp;
+    }
+
+    constexpr counted_iterator& operator--() requires bidirectional_iterator<_Iter> {
+        --_Current;
+        ++_Length;
+        return *this;
+    }
+
+    constexpr counted_iterator operator--(int) requires bidirectional_iterator<_Iter> {
+        counted_iterator _Tmp = *this;
+        --_Current;
+        ++_Length;
+        return _Tmp;
+    }
+
+    _NODISCARD constexpr counted_iterator operator+(const iter_difference_t<_Iter> _Diff) const
+        requires random_access_iterator<_Iter> {
+        return counted_iterator{_Current + _Diff, static_cast<iter_difference_t<_Iter>>(_Length - _Diff)};
+    }
+
+    _NODISCARD friend constexpr counted_iterator operator+(
+        const iter_difference_t<_Iter> _Diff, const counted_iterator& _Right) requires random_access_iterator<_Iter> {
+        return counted_iterator{_Right._Current + _Diff, static_cast<iter_difference_t<_Iter>>(_Right._Length - _Diff)};
+    }
+
+    constexpr counted_iterator& operator+=(
+        const iter_difference_t<_Iter> _Diff) requires random_access_iterator<_Iter> {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _STL_VERIFY(_Diff <= _Length, "counted_iterator seek beyond end of range");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        _Current += _Diff;
+        _Length -= _Diff;
+        return *this;
+    }
+
+    _NODISCARD constexpr counted_iterator operator-(const iter_difference_t<_Iter> _Diff) const
+        requires random_access_iterator<_Iter> {
+        return counted_iterator{_Current - _Diff, static_cast<iter_difference_t<_Iter>>(_Length + _Diff)};
+    }
+
+    template <common_with<_Iter> _Other>
+    _NODISCARD friend constexpr iter_difference_t<_Other> operator-(
+        const counted_iterator& _Left, const counted_iterator<_Other>& _Right) noexcept /* strengthened */ {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _Same_sequence(_Left, _Right);
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        return _Right.count() - _Left._Length;
+    }
+
+    _NODISCARD friend constexpr iter_difference_t<_Iter> operator-(
+        const counted_iterator& _Left, default_sentinel_t) noexcept /* strengthened */ {
+        return -_Left._Length;
+    }
+
+    _NODISCARD friend constexpr iter_difference_t<_Iter> operator-(
+        default_sentinel_t, const counted_iterator& _Right) noexcept /* strengthened */ {
+        return _Right._Length;
+    }
+
+    constexpr counted_iterator& operator-=(
+        const iter_difference_t<_Iter> _Diff) requires random_access_iterator<_Iter> {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _STL_VERIFY(-_Diff <= _Length, "counted_iterator decrement beyond end of range");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        _Current -= _Diff;
+        _Length += _Diff;
+        return *this;
+    }
+
+    // [counted.iter.cmp]
+    template <common_with<_Iter> _Other>
+    _NODISCARD friend constexpr bool operator==(
+        const counted_iterator& _Left, const counted_iterator<_Other>& _Right) noexcept /* strengthened */ {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _Same_sequence(_Left, _Right);
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        return _Left._Length == _Right.count();
+    }
+
+    _NODISCARD friend constexpr bool operator==(const counted_iterator& _Left, default_sentinel_t) noexcept
+    /* strengthened */ {
+        return _Left._Length == 0;
+    }
+
+    template <common_with<_Iter> _Other>
+    _NODISCARD friend constexpr strong_ordering operator<=>(
+        const counted_iterator& _Left, const counted_iterator<_Other>& _Right) noexcept /* strengthened */ {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _Same_sequence(_Left, _Right);
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        return _Right.count() <=> _Left._Length;
+    }
+
+    // [counted.iter.cust]
+    _NODISCARD friend constexpr iter_rvalue_reference_t<_Iter> iter_move(const counted_iterator& _Right) noexcept(
+        noexcept(_RANGES iter_move(_Right._Current))) requires input_iterator<_Iter> {
+        return _RANGES iter_move(_Right._Current);
+    }
+
+    template <indirectly_swappable<_Iter> _Other>
+    friend constexpr void iter_swap(const counted_iterator& _Left, const counted_iterator<_Other>& _Right) noexcept(
+        noexcept(_RANGES iter_swap(_Left._Current, _Right._Current))) {
+        _RANGES iter_swap(_Left._Current, _Right._Current);
+    }
+
+    template <common_with<_Iter> _Other>
+    friend constexpr void _Same_sequence(
+        const counted_iterator& _Left, const counted_iterator<_Other>& _Right) noexcept {
+        // Per N4861 [counted.iterator]/2, two counted_iterators x and y refer to elements of the same sequence iff
+        // next(x.base(), x.count()) and next(y.base(), y.count()) "refer to the same element." Iterator equality is a
+        // fair proxy for this condition.
+        if constexpr (forward_iterator<_Iter> && forward_iterator<_Other>) {
+            using _CIter = common_type_t<_Iter, _Other>;
+            using _CDiff = common_type_t<iter_difference_t<_Iter>, iter_difference_t<_Other>>;
+
+            const _CDiff _Diff = static_cast<_CDiff>(_Left._Length) - static_cast<_CDiff>(_Right.count());
+            if (_Diff < 0) {
+                _STL_VERIFY(
+                    static_cast<_CIter>(_Left._Current) == _RANGES next(static_cast<_CIter>(_Right.base()), -_Diff),
+                    "counted_iterators from different ranges");
+            } else {
+                _STL_VERIFY(
+                    _RANGES next(static_cast<_CIter>(_Left._Current), _Diff) == static_cast<_CIter>(_Right.base()),
+                    "counted_iterators from different ranges");
+            }
+        }
+    }
+
+    template <common_with<_Iter> _Other>
+    friend constexpr void _Verify_range(const counted_iterator& _Left, const counted_iterator<_Other>& _Right) {
+        if constexpr (_Range_verifiable_v<_Iter, _Other>) {
+            _Verify_range(_Left._Current, _Right._Current);
+        }
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _Same_sequence(_Left, _Right);
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+    }
+
+    constexpr void _Verify_offset(const iter_difference_t<_Iter> _Off) const {
+#if _ITERATOR_DEBUG_LEVEL != 0
+        _STL_VERIFY(_Off <= _Length, "Offset larger than counted_iterator length");
+#endif // _ITERATOR_DEBUG_LEVEL != 0
+        if constexpr (_Offset_verifiable_v<_Iter>) {
+            _Current._Verify_offset(_Off);
+        }
+    }
+
+    using _Prevent_inheriting_unwrap = counted_iterator;
+
+    _NODISCARD constexpr counted_iterator<_Unwrapped_t<const _Iter&>>
+        _Unwrapped() const& requires _Unwrappable_v<const _Iter&> {
+        return static_cast<counted_iterator<_Unwrapped_t<const _Iter&>>>(_Current._Unwrapped());
+    }
+
+    _NODISCARD constexpr counted_iterator<_Unwrapped_t<_Iter>> _Unwrapped() && requires _Unwrappable_v<const _Iter&> {
+        return static_cast<counted_iterator<_Unwrapped_t<_Iter>>>(_STD move(_Current)._Unwrapped());
+    }
+
+    static constexpr bool _Unwrap_when_unverified = _Do_unwrap_when_unverified_v<_Iter>;
+
+    // clang-format off
+    template <class _Other>
+        requires _Wrapped_seekable_v<_Iter, const _Other&>
+    constexpr void _Seek_to(const counted_iterator<_Other>& _It) {
+        // clang-format on
+        _Current._Seek_to(_It._Current);
+        _Length = _It._Length;
+    }
+
+    // clang-format off
+    template <class _Other>
+        requires _Wrapped_seekable_v<_Iter, _Other>
+    constexpr void _Seek_to(counted_iterator<_Other>&& _It) {
+        // clang-format on
+        _Current._Seek_to(_STD move(_It)._Current);
+        _Length = _It._Length;
+    }
+
+private:
+    template <input_or_output_iterator>
+    friend class counted_iterator;
+
+    _Iter _Current{};
+    iter_difference_t<_Iter> _Length = 0;
+};
+
+template <class _Iter>
+struct incrementable_traits<counted_iterator<_Iter>> {
+    using difference_type = iter_difference_t<_Iter>;
+};
+
+template <input_iterator _Iter>
+struct iterator_traits<counted_iterator<_Iter>> : iterator_traits<_Iter> {
+    using pointer = void;
+};
+#endif // __cpp_lib_concepts
+
 _STD_END
 
 _STDEXT_BEGIN

stl/inc/xatomic.h

@@ -11,6 +11,9 @@
 
 #include <intrin0.h>
 #include <type_traits>
+#if defined(_WIN64) && (_MSC_FULL_VER < 192829203) // TRANSITION
+#include <intrin.h> // Visual Studio 2019 to define 128-bit CAS in <intrin0.h>
+#endif // defined(_WIN64) && (_MSC_FULL_VER < 192829203), TRANSITION
 
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)

stl/inc/xatomic_wait.h

@@ -49,7 +49,7 @@ void __stdcall __std_atomic_notify_all_direct(const void* _Storage) noexcept;
 // of one of those sizes whose value changes upon notify, hence "indirect". (As of 2020-07-24, this always uses the
 // fallback SRWLOCK and CONDITION_VARIABLE implementation but that is not contractual.)
 using _Atomic_wait_indirect_equal_callback_t = bool(__stdcall*)(
-    const void* _Storage, void* _Comparand, size_t _Size, void* _Param) noexcept;
+    const void* _Storage, void* _Comparand, size_t _Size, void* _Param) _NOEXCEPT_FNPTR;
 
 int __stdcall __std_atomic_wait_indirect(const void* _Storage, void* _Comparand, size_t _Size, void* _Param,
     _Atomic_wait_indirect_equal_callback_t _Are_equal, unsigned long _Remaining_timeout) noexcept;