[libc++][NFC] Simplify __split_buffer a bit (#114224)

This is possible since we're not using `__compressed_pair` anymore.

Author: philnik777

libcxx/include/__split_buffer

@@ -108,12 +108,6 @@ public:
 
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~__split_buffer();
 
-  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __alloc_rr& __alloc() _NOEXCEPT { return __alloc_; }
-  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const __alloc_rr& __alloc() const _NOEXCEPT { return __alloc_; }
-
-  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pointer& __end_cap() _NOEXCEPT { return __end_cap_; }
-  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const pointer& __end_cap() const _NOEXCEPT { return __end_cap_; }
-
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __begin_; }
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __begin_; }
 
@@ -129,15 +123,15 @@ public:
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool empty() const { return __end_ == __begin_; }
 
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type capacity() const {
-    return static_cast<size_type>(__end_cap() - __first_);
+    return static_cast<size_type>(__end_cap_ - __first_);
   }
 
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __front_spare() const {
     return static_cast<size_type>(__begin_ - __first_);
   }
 
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __back_spare() const {
-    return static_cast<size_type>(__end_cap() - __end_);
+    return static_cast<size_type>(__end_cap_ - __end_);
   }
 
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference front() { return *__begin_; }
@@ -196,7 +190,7 @@ public:
 private:
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer& __c, true_type)
       _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) {
-    __alloc() = std::move(__c.__alloc());
+    __alloc_ = std::move(__c.__alloc_);
   }
 
   _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT {}
@@ -225,14 +219,14 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __split_buffer<_Tp, _Allocator>::__invariants
       return false;
     if (__end_ != nullptr)
       return false;
-    if (__end_cap() != nullptr)
+    if (__end_cap_ != nullptr)
       return false;
   } else {
     if (__begin_ < __first_)
       return false;
     if (__end_ < __begin_)
       return false;
-    if (__end_cap() < __end_)
+    if (__end_cap_ < __end_)
       return false;
   }
   return true;
@@ -247,7 +241,7 @@ template <class _Tp, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n) {
   _ConstructTransaction __tx(&this->__end_, __n);
   for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
-    __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_));
+    __alloc_traits::construct(__alloc_, std::__to_address(__tx.__pos_));
   }
 }
 
@@ -262,7 +256,7 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void
 __split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x) {
   _ConstructTransaction __tx(&this->__end_, __n);
   for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
-    __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_), __x);
+    __alloc_traits::construct(__alloc_, std::__to_address(__tx.__pos_), __x);
   }
 }
 
@@ -277,14 +271,14 @@ template <class _Tp, class _Allocator>
 template <class _Iterator, class _Sentinel>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 void
 __split_buffer<_Tp, _Allocator>::__construct_at_end_with_sentinel(_Iterator __first, _Sentinel __last) {
-  __alloc_rr& __a = this->__alloc();
+  __alloc_rr& __a = __alloc_;
   for (; __first != __last; ++__first) {
-    if (__end_ == __end_cap()) {
-      size_type __old_cap = __end_cap() - __first_;
+    if (__end_ == __end_cap_) {
+      size_type __old_cap = __end_cap_ - __first_;
       size_type __new_cap = std::max<size_type>(2 * __old_cap, 8);
       __split_buffer __buf(__new_cap, 0, __a);
       for (pointer __p = __begin_; __p != __end_; ++__p, (void)++__buf.__end_)
-        __alloc_traits::construct(__buf.__alloc(), std::__to_address(__buf.__end_), std::move(*__p));
+        __alloc_traits::construct(__buf.__alloc_, std::__to_address(__buf.__end_), std::move(*__p));
       swap(__buf);
     }
     __alloc_traits::construct(__a, std::__to_address(this->__end_), *__first);
@@ -304,15 +298,15 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void
 __split_buffer<_Tp, _Allocator>::__construct_at_end_with_size(_ForwardIterator __first, size_type __n) {
   _ConstructTransaction __tx(&this->__end_, __n);
   for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void)++__first) {
-    __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_), *__first);
+    __alloc_traits::construct(__alloc_, std::__to_address(__tx.__pos_), *__first);
   }
 }
 
 template <class _Tp, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 inline void
 __split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type) {
   while (__begin_ != __new_begin)
-    __alloc_traits::destroy(__alloc(), std::__to_address(__begin_++));
+    __alloc_traits::destroy(__alloc_, std::__to_address(__begin_++));
 }
 
 template <class _Tp, class _Allocator>
@@ -325,7 +319,7 @@ template <class _Tp, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void
 __split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT {
   while (__new_last != __end_)
-    __alloc_traits::destroy(__alloc(), std::__to_address(--__end_));
+    __alloc_traits::destroy(__alloc_, std::__to_address(--__end_));
 }
 
 template <class _Tp, class _Allocator>
@@ -341,19 +335,19 @@ __split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __sta
   if (__cap == 0) {
     __first_ = nullptr;
   } else {
-    auto __allocation = std::__allocate_at_least(__alloc(), __cap);
+    auto __allocation = std::__allocate_at_least(__alloc_, __cap);
     __first_          = __allocation.ptr;
     __cap             = __allocation.count;
   }
   __begin_ = __end_ = __first_ + __start;
-  __end_cap()       = __first_ + __cap;
+  __end_cap_        = __first_ + __cap;
 }
 
 template <class _Tp, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>::~__split_buffer() {
   clear();
   if (__first_)
-    __alloc_traits::deallocate(__alloc(), __first_, capacity());
+    __alloc_traits::deallocate(__alloc_, __first_, capacity());
 }
 
 template <class _Tp, class _Allocator>
@@ -364,30 +358,30 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>::__split_buffer(__
       __end_(std::move(__c.__end_)),
       __end_cap_(std::move(__c.__end_cap_)),
       __alloc_(std::move(__c.__alloc_)) {
-  __c.__first_    = nullptr;
-  __c.__begin_    = nullptr;
-  __c.__end_      = nullptr;
-  __c.__end_cap() = nullptr;
+  __c.__first_   = nullptr;
+  __c.__begin_   = nullptr;
+  __c.__end_     = nullptr;
+  __c.__end_cap_ = nullptr;
 }
 
 template <class _Tp, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 __split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a)
     : __end_cap_(nullptr), __alloc_(__a) {
-  if (__a == __c.__alloc()) {
-    __first_        = __c.__first_;
-    __begin_        = __c.__begin_;
-    __end_          = __c.__end_;
-    __end_cap()     = __c.__end_cap();
-    __c.__first_    = nullptr;
-    __c.__begin_    = nullptr;
-    __c.__end_      = nullptr;
-    __c.__end_cap() = nullptr;
+  if (__a == __c.__alloc_) {
+    __first_       = __c.__first_;
+    __begin_       = __c.__begin_;
+    __end_         = __c.__end_;
+    __end_cap_     = __c.__end_cap_;
+    __c.__first_   = nullptr;
+    __c.__begin_   = nullptr;
+    __c.__end_     = nullptr;
+    __c.__end_cap_ = nullptr;
   } else {
-    auto __allocation = std::__allocate_at_least(__alloc(), __c.size());
+    auto __allocation = std::__allocate_at_least(__alloc_, __c.size());
     __first_          = __allocation.ptr;
     __begin_ = __end_ = __first_;
-    __end_cap()       = __first_ + __allocation.count;
+    __end_cap_        = __first_ + __allocation.count;
     typedef move_iterator<iterator> _Ip;
     __construct_at_end(_Ip(__c.begin()), _Ip(__c.end()));
   }
@@ -401,12 +395,12 @@ __split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c)
                !__alloc_traits::propagate_on_container_move_assignment::value) {
   clear();
   shrink_to_fit();
-  __first_    = __c.__first_;
-  __begin_    = __c.__begin_;
-  __end_      = __c.__end_;
-  __end_cap() = __c.__end_cap();
+  __first_   = __c.__first_;
+  __begin_   = __c.__begin_;
+  __end_     = __c.__end_;
+  __end_cap_ = __c.__end_cap_;
   __move_assign_alloc(__c, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
-  __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr;
+  __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap_ = nullptr;
   return *this;
 }
 
@@ -416,19 +410,19 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::swap(__split
   std::swap(__first_, __x.__first_);
   std::swap(__begin_, __x.__begin_);
   std::swap(__end_, __x.__end_);
-  std::swap(__end_cap(), __x.__end_cap());
-  std::__swap_allocator(__alloc(), __x.__alloc());
+  std::swap(__end_cap_, __x.__end_cap_);
+  std::__swap_allocator(__alloc_, __x.__alloc_);
 }
 
 template <class _Tp, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::reserve(size_type __n) {
   if (__n < capacity()) {
-    __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc());
+    __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc_);
     __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_));
     std::swap(__first_, __t.__first_);
     std::swap(__begin_, __t.__begin_);
     std::swap(__end_, __t.__end_);
-    std::swap(__end_cap(), __t.__end_cap());
+    std::swap(__end_cap_, __t.__end_cap_);
   }
 }
 
@@ -438,13 +432,13 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::shrink_to_fi
 #if _LIBCPP_HAS_EXCEPTIONS
     try {
 #endif // _LIBCPP_HAS_EXCEPTIONS
-      __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc());
+      __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc_);
       __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_));
       __t.__end_ = __t.__begin_ + (__end_ - __begin_);
       std::swap(__first_, __t.__first_);
       std::swap(__begin_, __t.__begin_);
       std::swap(__end_, __t.__end_);
-      std::swap(__end_cap(), __t.__end_cap());
+      std::swap(__end_cap_, __t.__end_cap_);
 #if _LIBCPP_HAS_EXCEPTIONS
     } catch (...) {
     }
@@ -456,45 +450,45 @@ template <class _Tp, class _Allocator>
 template <class... _Args>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::emplace_front(_Args&&... __args) {
   if (__begin_ == __first_) {
-    if (__end_ < __end_cap()) {
-      difference_type __d = __end_cap() - __end_;
+    if (__end_ < __end_cap_) {
+      difference_type __d = __end_cap_ - __end_;
       __d                 = (__d + 1) / 2;
       __begin_            = std::move_backward(__begin_, __end_, __end_ + __d);
       __end_ += __d;
     } else {
-      size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
-      __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
+      size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap_ - __first_), 1);
+      __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc_);
       __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_));
       std::swap(__first_, __t.__first_);
       std::swap(__begin_, __t.__begin_);
       std::swap(__end_, __t.__end_);
-      std::swap(__end_cap(), __t.__end_cap());
+      std::swap(__end_cap_, __t.__end_cap_);
     }
   }
-  __alloc_traits::construct(__alloc(), std::__to_address(__begin_ - 1), std::forward<_Args>(__args)...);
+  __alloc_traits::construct(__alloc_, std::__to_address(__begin_ - 1), std::forward<_Args>(__args)...);
   --__begin_;
 }
 
 template <class _Tp, class _Allocator>
 template <class... _Args>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args) {
-  if (__end_ == __end_cap()) {
+  if (__end_ == __end_cap_) {
     if (__begin_ > __first_) {
       difference_type __d = __begin_ - __first_;
       __d                 = (__d + 1) / 2;
       __end_              = std::move(__begin_, __end_, __begin_ - __d);
       __begin_ -= __d;
     } else {
-      size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
-      __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
+      size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap_ - __first_), 1);
+      __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc_);
       __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_));
       std::swap(__first_, __t.__first_);
       std::swap(__begin_, __t.__begin_);
       std::swap(__end_, __t.__end_);
-      std::swap(__end_cap(), __t.__end_cap());
+      std::swap(__end_cap_, __t.__end_cap_);
     }
   }
-  __alloc_traits::construct(__alloc(), std::__to_address(__end_), std::forward<_Args>(__args)...);
+  __alloc_traits::construct(__alloc_, std::__to_address(__end_), std::forward<_Args>(__args)...);
   ++__end_;
 }
 

libcxx/include/__vector/vector.h

@@ -822,7 +822,7 @@ vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, a
   __end_       = __begin_; // All the objects have been destroyed by relocating them.
   std::swap(this->__begin_, __v.__begin_);
   std::swap(this->__end_, __v.__end_);
-  std::swap(this->__end_cap(), __v.__end_cap());
+  std::swap(this->__end_cap(), __v.__end_cap_);
   __v.__first_ = __v.__begin_;
   __annotate_new(size());
 }
@@ -852,7 +852,7 @@ vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, a
 
   std::swap(this->__begin_, __v.__begin_);
   std::swap(this->__end_, __v.__end_);
-  std::swap(this->__end_cap(), __v.__end_cap());
+  std::swap(this->__end_cap(), __v.__end_cap_);
   __v.__first_ = __v.__begin_;
   __annotate_new(size());
   return __ret;