Simplify string a bit

Author: winner245

libcxx/include/string

@@ -2335,7 +2335,7 @@ private:
       if (!__str.__is_long()) {
         if (__is_long()) {
           __annotate_delete();
-          __alloc_traits::deallocate(__alloc_, __get_long_pointer(), capacity() + 1);
+          __alloc_traits::deallocate(__alloc_, __get_long_pointer(), __get_long_cap());
           __rep_ = __rep();
         }
         __alloc_ = __str.__alloc_;
@@ -2350,7 +2350,7 @@ private:
         __alloc_ = std::move(__a);
         __set_long_pointer(__allocation.ptr);
         __set_long_cap(__allocation.count);
-        __set_long_size(__str.size());
+        __set_long_size(__str.__get_long_size());
       }
     }
   }
@@ -2470,8 +2470,8 @@ template <class _CharT,
           class _Traits,
           class _Allocator = allocator<_CharT>,
           class            = enable_if_t<__is_allocator<_Allocator>::value> >
-explicit basic_string(basic_string_view<_CharT, _Traits>,
-                      const _Allocator& = _Allocator()) -> basic_string<_CharT, _Traits, _Allocator>;
+explicit basic_string(basic_string_view<_CharT, _Traits>, const _Allocator& = _Allocator())
+    -> basic_string<_CharT, _Traits, _Allocator>;
 
 template <class _CharT,
           class _Traits,
@@ -2758,20 +2758,19 @@ template <class _CharT, class _Traits, class _Allocator>
 template <bool __is_short>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::__assign_no_alias(const value_type* __s, size_type __n) {
-  size_type __cap = __is_short ? static_cast<size_type>(__min_cap) : __get_long_cap();
-  if (__n < __cap) {
-    size_type __old_size = __is_short ? __get_short_size() : __get_long_size();
+  size_type __old_size = size();
+  size_type __old_cap  = capacity();
+  if (__n <= __old_cap) {
     if (__n > __old_size)
       __annotate_increase(__n - __old_size);
-    pointer __p = __is_short ? __get_short_pointer() : __get_long_pointer();
-    __is_short ? __set_short_size(__n) : __set_long_size(__n);
+    pointer __p =
+        __is_long() ? (__set_long_size(__n), __get_long_pointer()) : (__set_short_size(__n), __get_short_pointer());
     traits_type::copy(std::__to_address(__p), __s, __n);
     traits_type::assign(__p[__n], value_type());
     if (__old_size > __n)
       __annotate_shrink(__old_size);
   } else {
-    size_type __sz = __is_short ? __get_short_size() : __get_long_size();
-    __grow_by_and_replace(__cap - 1, __n - __cap + 1, __sz, 0, __sz, __n, __s);
+    __grow_by_and_replace(__old_cap, __n - __old_cap, __old_size, 0, __old_size, __n, __s);
   }
   return *this;
 }
@@ -2820,17 +2819,10 @@ basic_string<_CharT, _Traits, _Allocator>::assign(size_type __n, value_type __c)
 template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::operator=(value_type __c) {
-  pointer __p;
   size_type __old_size = size();
   if (__old_size == 0)
     __annotate_increase(1);
-  if (__is_long()) {
-    __p = __get_long_pointer();
-    __set_long_size(1);
-  } else {
-    __p = __get_short_pointer();
-    __set_short_size(1);
-  }
+  pointer __p = __is_long() ? (__set_long_size(1), __get_long_pointer()) : (__set_short_size(1), __get_short_pointer());
   traits_type::assign(*__p, __c);
   traits_type::assign(*++__p, value_type());
   if (__old_size > 1)
@@ -3093,14 +3085,8 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::pu
     __is_short = false; // the string is always long after __grow_by
   } else
     __annotate_increase(1);
-  pointer __p = __get_pointer();
-  if (__is_short) {
-    __p = __get_short_pointer() + __sz;
-    __set_short_size(__sz + 1);
-  } else {
-    __p = __get_long_pointer() + __sz;
-    __set_long_size(__sz + 1);
-  }
+  pointer __p = __is_short ? (__set_short_size(__sz + 1), __get_short_pointer() + __sz)
+                           : (__set_long_size(__sz + 1), __get_long_pointer() + __sz);
   traits_type::assign(*__p, __c);
   traits_type::assign(*++__p, value_type());
 }
@@ -3477,11 +3463,13 @@ inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocat
 
 template <class _CharT, class _Traits, class _Allocator>
 inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::clear() _NOEXCEPT {
-  size_type __old_size = size();
+  size_type __old_size;
   if (__is_long()) {
+    __old_size = __get_long_size();
     traits_type::assign(*__get_long_pointer(), value_type());
     __set_long_size(0);
   } else {
+    __old_size = __get_short_size();
     traits_type::assign(*__get_short_pointer(), value_type());
     __set_short_size(0);
   }
@@ -3539,11 +3527,12 @@ inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocat
   _LIBCPP_ASSERT_INTERNAL(__is_long(), "Trying to shrink small string");
 
   // We're a long string and we're shrinking into the small buffer.
+  auto __ptr  = __get_long_pointer();
+  auto __size = __get_long_size();
+  auto __cap  = __get_long_cap();
+
   if (__fits_in_sso(__target_capacity)) {
     __annotation_guard __g(*this);
-    auto __ptr  = __get_long_pointer();
-    auto __size = __get_long_size();
-    auto __cap  = __get_long_cap();
     traits_type::copy(std::__to_address(__get_short_pointer()), std::__to_address(__ptr), __size + 1);
     __set_short_size(__size);
     __alloc_traits::deallocate(__alloc_, __ptr, __cap);
@@ -3554,21 +3543,19 @@ inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocat
   try {
 #  endif // _LIBCPP_HAS_EXCEPTIONS
     __annotation_guard __g(*this);
-    auto __size       = size();
     auto __allocation = std::__allocate_at_least(__alloc_, __target_capacity + 1);
 
     // The Standard mandates shrink_to_fit() does not increase the capacity.
     // With equal capacity keep the existing buffer. This avoids extra work
     // due to swapping the elements.
-    if (__allocation.count - 1 > capacity()) {
+    if (__allocation.count > __cap) {
       __alloc_traits::deallocate(__alloc_, __allocation.ptr, __allocation.count);
       return;
     }
 
     __begin_lifetime(__allocation.ptr, __allocation.count);
-    auto __ptr = __get_long_pointer();
     traits_type::copy(std::__to_address(__allocation.ptr), std::__to_address(__ptr), __size + 1);
-    __alloc_traits::deallocate(__alloc_, __ptr, __get_long_cap());
+    __alloc_traits::deallocate(__alloc_, __ptr, __cap);
     __set_long_cap(__allocation.count);
     __set_long_pointer(__allocation.ptr);
 #  if _LIBCPP_HAS_EXCEPTIONS