From bb9ad59f42160d12ea3db9c4d01d06c67cd00559 Mon Sep 17 00:00:00 2001
From: achabense <60953653+achabense@users.noreply.github.com>
Date: Wed, 8 Oct 2025 11:39:41 +0800
Subject: [PATCH 1/4] Remove `_Assign`

---
 stl/inc/any | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/stl/inc/any b/stl/inc/any
index 9aba1b3fb41..3254308a717 100644
--- a/stl/inc/any
+++ b/stl/inc/any
@@ -176,12 +176,16 @@ public:
 
     // Assignment [any.assign]
     any& operator=(const any& _That) {
-        _Assign(_That);
+        any _Tmp = _That;
+        reset();
+        _Move_from(_Tmp);
         return *this;
     }
 
     any& operator=(any&& _That) noexcept {
-        _Assign(_STD move(_That));
+        any _Tmp = _STD move(_That);
+        reset();
+        _Move_from(_Tmp);
         return *this;
     }
 
@@ -190,7 +194,9 @@ public:
                                     int> = 0>
     any& operator=(_ValueType&& _Value) {
         // replace contained value with an object of type decay_t<_ValueType> initialized from _Value
-        _Assign(_STD forward<_ValueType>(_Value));
+        any _Tmp = _STD forward<_ValueType>(_Value);
+        reset();
+        _Move_from(_Tmp);
         return *this;
     }
 
@@ -306,11 +312,6 @@ private:
         }
     }
 
-    void _Assign(any _That) noexcept { // intentionally pass by value
-        reset();
-        _Move_from(_That);
-    }
-
     template <class _Decayed, class... _Types>
     _Decayed& _Emplace(_Types&&... _Args) { // emplace construct _Decayed
         if constexpr (_Any_is_trivial<_Decayed>) {

From 2294cfeae4951fc2a46c533915350ee543f9eaf6 Mon Sep 17 00:00:00 2001
From: achabense <60953653+achabense@users.noreply.github.com>
Date: Wed, 8 Oct 2025 11:40:41 +0800
Subject: [PATCH 2/4] Combine `reset` and `_Move_from`

---
 stl/inc/any | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/stl/inc/any b/stl/inc/any
index 3254308a717..39a789a3238 100644
--- a/stl/inc/any
+++ b/stl/inc/any
@@ -177,15 +177,13 @@ public:
     // Assignment [any.assign]
     any& operator=(const any& _That) {
         any _Tmp = _That;
-        reset();
-        _Move_from(_Tmp);
+        _Reset_and_move_from(_Tmp);
         return *this;
     }
 
     any& operator=(any&& _That) noexcept {
         any _Tmp = _STD move(_That);
-        reset();
-        _Move_from(_Tmp);
+        _Reset_and_move_from(_Tmp);
         return *this;
     }
 
@@ -195,8 +193,7 @@ public:
     any& operator=(_ValueType&& _Value) {
         // replace contained value with an object of type decay_t<_ValueType> initialized from _Value
         any _Tmp = _STD forward<_ValueType>(_Value);
-        reset();
-        _Move_from(_Tmp);
+        _Reset_and_move_from(_Tmp);
         return *this;
     }
 
@@ -237,10 +234,8 @@ public:
 
     void swap(any& _That) noexcept {
         any _Old = _STD move(*this);
-        reset();
-        _Move_from(_That);
-        _That.reset();
-        _That._Move_from(_Old);
+        _Reset_and_move_from(_That);
+        _That._Reset_and_move_from(_Old);
     }
 
     // Observers [any.observers]
@@ -312,6 +307,11 @@ private:
         }
     }
 
+    void _Reset_and_move_from(any& _That) noexcept {
+        reset();
+        _Move_from(_That);
+    }
+
     template <class _Decayed, class... _Types>
     _Decayed& _Emplace(_Types&&... _Args) { // emplace construct _Decayed
         if constexpr (_Any_is_trivial<_Decayed>) {

From fb0fb10be958e17a1c51412fc21cde9ad1ba8a3f Mon Sep 17 00:00:00 2001
From: achabense <60953653+achabense@users.noreply.github.com>
Date: Wed, 15 Oct 2025 18:35:35 +0800
Subject: [PATCH 3/4] Precondition

---
 stl/inc/any | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/stl/inc/any b/stl/inc/any
index 39a789a3238..1d2518ab598 100644
--- a/stl/inc/any
+++ b/stl/inc/any
@@ -289,6 +289,7 @@ private:
     }
 
     void _Move_from(any& _That) noexcept {
+        _STL_INTERNAL_CHECK(_Storage._TypeData == 0); // !has_value()
         _Storage._TypeData = _That._Storage._TypeData;
         switch (_Rep()) {
         case _Any_representation::_Small:
@@ -314,6 +315,7 @@ private:
 
     template <class _Decayed, class... _Types>
     _Decayed& _Emplace(_Types&&... _Args) { // emplace construct _Decayed
+        _STL_INTERNAL_CHECK(_Storage._TypeData == 0); // !has_value()
         if constexpr (_Any_is_trivial<_Decayed>) {
             // using the _Trivial representation
             auto& _Obj = reinterpret_cast<_Decayed&>(_Storage._TrivialData);

From 3e12cc1f6f3cee4e9825f913e5c87326052c6385 Mon Sep 17 00:00:00 2001
From: achabense <60953653+achabense@users.noreply.github.com>
Date: Wed, 15 Oct 2025 18:47:03 +0800
Subject: [PATCH 4/4] Use `_Tmp` (which is more regularly used in this project
 e.g. std::swap and ranges::swap)

---
 stl/inc/any | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/stl/inc/any b/stl/inc/any
index 1d2518ab598..c9d30736a57 100644
--- a/stl/inc/any
+++ b/stl/inc/any
@@ -233,9 +233,9 @@ public:
     }
 
     void swap(any& _That) noexcept {
-        any _Old = _STD move(*this);
+        any _Tmp = _STD move(*this);
         _Reset_and_move_from(_That);
-        _That._Reset_and_move_from(_Old);
+        _That._Reset_and_move_from(_Tmp);
     }
 
     // Observers [any.observers]