diff --git a/libcxx/include/string b/libcxx/include/string
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -1529,15 +1529,16 @@
         size_type __align_it(size_type __s) _NOEXCEPT
             {return (__s + (__a-1)) & ~(__a-1);}
     enum {__alignment = 16};
-    static _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_HIDE_FROM_ABI
     size_type __recommend(size_type __s) _NOEXCEPT
-        {
-        if (__s < __min_cap) return static_cast<size_type>(__min_cap) - 1;
-        size_type __guess = __align_it<sizeof(value_type) < __alignment ?
-                     __alignment/sizeof(value_type) : 1 > (__s+1) - 1;
-        if (__guess == __min_cap) ++__guess;
+    {
+        if (__s < __min_cap)
+            return static_cast<size_type>(__min_cap);
+        size_type __guess = __align_it<sizeof(value_type) <__alignment ? __alignment / sizeof(value_type) : 1> (__s + 1);
+        if (__guess == __min_cap)
+            ++__guess;
         return __guess;
-        }
+    }
 
     inline
     void __init(const value_type* __s, size_type __sz, size_type __reserve);
@@ -1830,12 +1831,12 @@
     else
     {
         size_type __cap = __recommend(__reserve);
-        __p = __alloc_traits::allocate(__alloc(), __cap+1);
+        __p = __alloc_traits::allocate(__alloc(), __cap);
         __set_long_pointer(__p);
-        __set_long_cap(__cap+1);
+        __set_long_cap(__cap);
         __set_long_size(__sz);
     }
-    traits_type::copy(_VSTD::__to_address(__p), __s, __sz);
+    traits_type::copy(std::__to_address(__p), __s, __sz);
     traits_type::assign(__p[__sz], value_type());
 }
 
@@ -1854,12 +1855,12 @@
     else
     {
         size_type __cap = __recommend(__sz);
-        __p = __alloc_traits::allocate(__alloc(), __cap+1);
+        __p = __alloc_traits::allocate(__alloc(), __cap);
         __set_long_pointer(__p);
-        __set_long_cap(__cap+1);
+        __set_long_cap(__cap);
         __set_long_size(__sz);
     }
-    traits_type::copy(_VSTD::__to_address(__p), __s, __sz);
+    traits_type::copy(std::__to_address(__p), __s, __sz);
     traits_type::assign(__p[__sz], value_type());
 }
 
@@ -1929,12 +1930,12 @@
     if (__sz > max_size())
       __throw_length_error();
     size_t __cap = __recommend(__sz);
-    __p = __alloc_traits::allocate(__alloc(), __cap + 1);
+    __p = __alloc_traits::allocate(__alloc(), __cap);
     __set_long_pointer(__p);
-    __set_long_cap(__cap + 1);
+    __set_long_cap(__cap);
     __set_long_size(__sz);
   }
-  traits_type::copy(_VSTD::__to_address(__p), __s, __sz + 1);
+  traits_type::copy(std::__to_address(__p), __s, __sz + 1);
 }
 
 #ifndef _LIBCPP_CXX03_LANG
@@ -1993,12 +1994,12 @@
     else
     {
         size_type __cap = __recommend(__n);
-        __p = __alloc_traits::allocate(__alloc(), __cap+1);
+        __p = __alloc_traits::allocate(__alloc(), __cap);
         __set_long_pointer(__p);
-        __set_long_cap(__cap+1);
+        __set_long_cap(__cap);
         __set_long_size(__n);
     }
-    traits_type::assign(_VSTD::__to_address(__p), __n, __c);
+    traits_type::assign(std::__to_address(__p), __n, __c);
     traits_type::assign(__p[__n], value_type());
 }
 
@@ -2124,9 +2125,9 @@
     else
     {
         size_type __cap = __recommend(__sz);
-        __p = __alloc_traits::allocate(__alloc(), __cap+1);
+        __p = __alloc_traits::allocate(__alloc(), __cap);
         __set_long_pointer(__p);
-        __set_long_cap(__cap+1);
+        __set_long_cap(__cap);
         __set_long_size(__sz);
     }
 
@@ -2216,9 +2217,9 @@
         __throw_length_error();
     pointer __old_p = __get_pointer();
     size_type __cap = __old_cap < __ms / 2 - __alignment ?
-                          __recommend(_VSTD::max(__old_cap + __delta_cap, 2 * __old_cap)) :
+                          __recommend(std::max(__old_cap + __delta_cap, 2 * __old_cap)) :
                           __ms - 1;
-    pointer __p = __alloc_traits::allocate(__alloc(), __cap+1);
+    pointer __p = __alloc_traits::allocate(__alloc(), __cap);
     __invalidate_all_iterators();
     if (__n_copy != 0)
         traits_type::copy(_VSTD::__to_address(__p),
@@ -2232,7 +2233,7 @@
     if (__old_cap+1 != __min_cap)
         __alloc_traits::deallocate(__alloc(), __old_p, __old_cap+1);
     __set_long_pointer(__p);
-    __set_long_cap(__cap+1);
+    __set_long_cap(__cap);
     __old_sz = __n_copy + __n_add + __sec_cp_sz;
     __set_long_size(__old_sz);
     traits_type::assign(__p[__old_sz], value_type());
@@ -2248,9 +2249,9 @@
         __throw_length_error();
     pointer __old_p = __get_pointer();
     size_type __cap = __old_cap < __ms / 2 - __alignment ?
-                          __recommend(_VSTD::max(__old_cap + __delta_cap, 2 * __old_cap)) :
+                          __recommend(std::max(__old_cap + __delta_cap, 2 * __old_cap)) :
                           __ms - 1;
-    pointer __p = __alloc_traits::allocate(__alloc(), __cap+1);
+    pointer __p = __alloc_traits::allocate(__alloc(), __cap);
     __invalidate_all_iterators();
     if (__n_copy != 0)
         traits_type::copy(_VSTD::__to_address(__p),
@@ -2263,7 +2264,7 @@
     if (__old_cap+1 != __min_cap)
         __alloc_traits::deallocate(__alloc(), __old_p, __old_cap+1);
     __set_long_pointer(__p);
-    __set_long_cap(__cap+1);
+    __set_long_cap(__cap);
 }
 
 // assign
@@ -3228,7 +3229,7 @@
 
     size_type __target_capacity = _VSTD::max(__requested_capacity, size());
     __target_capacity = __recommend(__target_capacity);
-    if (__target_capacity == capacity()) return;
+    if (__target_capacity == capacity() + 1) return;
 
     __shrink_or_extend(__target_capacity);
 }
@@ -3239,7 +3240,7 @@
 basic_string<_CharT, _Traits, _Allocator>::shrink_to_fit() _NOEXCEPT
 {
     size_type __target_capacity = __recommend(size());
-    if (__target_capacity == capacity()) return;
+    if (__target_capacity == capacity() + 1) return;
 
     __shrink_or_extend(__target_capacity);
 }