[P0980R1] constexpr std::string

stl/inc/vector

@@ -126,7 +126,8 @@ public:
 
     _NODISCARD _CONSTEXPR20_CONTAINER _Vector_const_iterator operator+(const difference_type _Off) const noexcept {
         _Vector_const_iterator _Tmp = *this;
-        return _Tmp += _Off;
+        _Tmp += _Off; // TRANSITION, LLVM-49342
+        return _Tmp;
     }
 
     _CONSTEXPR20_CONTAINER _Vector_const_iterator& operator-=(const difference_type _Off) noexcept {
@@ -135,7 +136,8 @@ public:
 
     _NODISCARD _CONSTEXPR20_CONTAINER _Vector_const_iterator operator-(const difference_type _Off) const noexcept {
         _Vector_const_iterator _Tmp = *this;
-        return _Tmp -= _Off;
+        _Tmp -= _Off; // TRANSITION, LLVM-49342
+        return _Tmp;
     }
 
     _NODISCARD _CONSTEXPR20_CONTAINER difference_type operator-(const _Vector_const_iterator& _Right) const noexcept {
@@ -307,7 +309,8 @@ public:
 
     _NODISCARD _CONSTEXPR20_CONTAINER _Vector_iterator operator+(const difference_type _Off) const noexcept {
         _Vector_iterator _Tmp = *this;
-        return _Tmp += _Off;
+        _Tmp += _Off; // TRANSITION, LLVM-49342
+        return _Tmp;
     }
 
     _CONSTEXPR20_CONTAINER _Vector_iterator& operator-=(const difference_type _Off) noexcept {
@@ -319,7 +322,8 @@ public:
 
     _NODISCARD _CONSTEXPR20_CONTAINER _Vector_iterator operator-(const difference_type _Off) const noexcept {
         _Vector_iterator _Tmp = *this;
-        return _Tmp -= _Off;
+        _Tmp -= _Off; // TRANSITION, LLVM-49342
+        return _Tmp;
     }
 
     _NODISCARD _CONSTEXPR20_CONTAINER reference operator[](const difference_type _Off) const noexcept {
@@ -2185,7 +2189,8 @@ public:
 
     _NODISCARD _CONSTEXPR20_CONTAINER _Vb_const_iterator operator+(const difference_type _Off) const noexcept {
         _Vb_const_iterator _Tmp = *this;
-        return _Tmp += _Off;
+        _Tmp += _Off; // TRANSITION, LLVM-49342
+        return _Tmp;
     }
 
     _CONSTEXPR20_CONTAINER _Vb_const_iterator& operator-=(const difference_type _Off) noexcept {
@@ -2194,7 +2199,8 @@ public:
 
     _NODISCARD _CONSTEXPR20_CONTAINER _Vb_const_iterator operator-(const difference_type _Off) const noexcept {
         _Vb_const_iterator _Tmp = *this;
-        return _Tmp -= _Off;
+        _Tmp -= _Off; // TRANSITION, LLVM-49342
+        return _Tmp;
     }
 
     _NODISCARD _CONSTEXPR20_CONTAINER difference_type operator-(const _Vb_const_iterator& _Right) const noexcept {
@@ -2363,7 +2369,8 @@ public:
 
     _NODISCARD _CONSTEXPR20_CONTAINER _Vb_iterator operator+(const difference_type _Off) const noexcept {
         _Vb_iterator _Tmp = *this;
-        return _Tmp += _Off;
+        _Tmp += _Off; // TRANSITION, LLVM-49342
+        return _Tmp;
     }
 
     _CONSTEXPR20_CONTAINER _Vb_iterator& operator-=(const difference_type _Off) noexcept {
@@ -2375,7 +2382,8 @@ public:
 
     _NODISCARD _CONSTEXPR20_CONTAINER _Vb_iterator operator-(const difference_type _Off) const noexcept {
         _Vb_iterator _Tmp = *this;
-        return _Tmp -= _Off;
+        _Tmp -= _Off; // TRANSITION, LLVM-49342
+        return _Tmp;
     }
 
     _NODISCARD _CONSTEXPR20_CONTAINER reference operator[](const difference_type _Off) const noexcept {

stl/inc/xmemory

@@ -1178,8 +1178,8 @@ public:
 
     static constexpr bool _Unwrap_when_unverified = _ITERATOR_DEBUG_LEVEL == 0;
 
-    _Container_proxy* _Myproxy    = nullptr;
-    _Iterator_base12* _Mynextiter = nullptr;
+    mutable _Container_proxy* _Myproxy    = nullptr;
+    mutable _Iterator_base12* _Mynextiter = nullptr;
 
 #if _ITERATOR_DEBUG_LEVEL == 2
 private:
@@ -1338,7 +1338,8 @@ struct _Container_proxy_ptr12 : _Basic_container_proxy_ptr12 {
 };
 
 #if _ITERATOR_DEBUG_LEVEL == 0
-#define _GET_PROXY_ALLOCATOR(_Alty, _Al) _Fake_allocator()
+_INLINE_VAR constexpr _Fake_allocator _Fake_alloc{};
+#define _GET_PROXY_ALLOCATOR(_Alty, _Al) _Fake_alloc // TRANSITION, VSO-1284799, should be _Fake_allocator{}
 template <class _Alloc>
 using _Container_proxy_ptr = _Fake_proxy_ptr_impl;
 #else // _ITERATOR_DEBUG_LEVEL == 0