diff --git a/include/string b/include/string
index ac7b30a..6be2195 100644
--- a/include/string
+++ b/include/string
@@ -220,8 +220,8 @@
     basic_string substr(size_type pos = 0, size_type n = npos) const;
 
     void swap(basic_string& str)
-        noexcept(!allocator_type::propagate_on_container_swap::value ||
-                 __is_nothrow_swappable<allocator_type>::value)
+        noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||
+                 allocator_traits<allocator_type>::is_always_equal::value);  // C++17
 
     const value_type* c_str() const noexcept;
     const value_type* data() const noexcept;
@@ -1604,8 +1604,12 @@
 
     _LIBCPP_INLINE_VISIBILITY
     void swap(basic_string& __str)
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                   __is_nothrow_swappable<allocator_type>::value);
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT;
+#else
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || 
+                    __is_nothrow_swappable<allocator_type>::value);
+#endif
 
     _LIBCPP_INLINE_VISIBILITY
     const value_type* c_str() const _NOEXCEPT {return data();}
@@ -1868,24 +1872,6 @@
         _NOEXCEPT
         {}
 
-    _LIBCPP_INLINE_VISIBILITY
-    static void __swap_alloc(allocator_type& __x, allocator_type& __y)
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                   __is_nothrow_swappable<allocator_type>::value)
-        {__swap_alloc(__x, __y, integral_constant<bool,
-                      __alloc_traits::propagate_on_container_swap::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void __swap_alloc(allocator_type& __x, allocator_type& __y, true_type)
-        _NOEXCEPT_(__is_nothrow_swappable<allocator_type>::value)
-        {
-            using _VSTD::swap;
-            swap(__x, __y);
-        }
-    _LIBCPP_INLINE_VISIBILITY
-    static void __swap_alloc(allocator_type&, allocator_type&, false_type) _NOEXCEPT
-        {}
-
     _LIBCPP_INLINE_VISIBILITY void __invalidate_all_iterators();
     _LIBCPP_INLINE_VISIBILITY void __invalidate_iterators_past(size_type);
 
@@ -3366,8 +3352,12 @@
 inline _LIBCPP_INLINE_VISIBILITY
 void
 basic_string<_CharT, _Traits, _Allocator>::swap(basic_string& __str)
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                   __is_nothrow_swappable<allocator_type>::value)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT
+#else
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || 
+                    __is_nothrow_swappable<allocator_type>::value)
+#endif
 {
 #if _LIBCPP_DEBUG_LEVEL >= 2
     if (!__is_long())
@@ -3377,7 +3367,7 @@
     __get_db()->swap(this, &__str);
 #endif
     _VSTD::swap(__r_.first(), __str.__r_.first());
-    __swap_alloc(__alloc(), __str.__alloc());
+    __swap_allocator(__alloc(), __str.__alloc());
 }
 
 // find