diff --git a/libcxx/include/vector b/libcxx/include/vector
--- a/libcxx/include/vector
+++ b/libcxx/include/vector
@@ -439,7 +439,7 @@
     _LIBCPP_INLINE_VISIBILITY
     vector(vector&& __x)
 #if _LIBCPP_STD_VER > 14
-        _NOEXCEPT;
+        noexcept;
 #else
         _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
 #endif
@@ -567,41 +567,26 @@
     const value_type* data() const _NOEXCEPT
         {return _VSTD::__to_address(this->__begin_);}
 
-#ifdef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void __emplace_back(const value_type& __x) { push_back(__x); }
-#else
-    template <class _Arg>
-    _LIBCPP_INLINE_VISIBILITY
-    void __emplace_back(_Arg&& __arg) {
-      emplace_back(_VSTD::forward<_Arg>(__arg));
-    }
-#endif
-
     _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
 
-#ifndef _LIBCPP_CXX03_LANG
     _LIBCPP_INLINE_VISIBILITY void push_back(value_type&& __x);
 
     template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY
 #if _LIBCPP_STD_VER > 14
         reference emplace_back(_Args&&... __args);
 #else
         void      emplace_back(_Args&&... __args);
 #endif
-#endif // !_LIBCPP_CXX03_LANG
 
     _LIBCPP_INLINE_VISIBILITY
     void pop_back();
 
     iterator insert(const_iterator __position, const_reference __x);
 
-#ifndef _LIBCPP_CXX03_LANG
     iterator insert(const_iterator __position, value_type&& __x);
     template <class... _Args>
-        iterator emplace(const_iterator __position, _Args&&... __args);
-#endif // !_LIBCPP_CXX03_LANG
+    iterator emplace(const_iterator __position, _Args&&... __args);
 
     iterator insert(const_iterator __position, size_type __n, const_reference __x);
     template <class _InputIterator>
@@ -727,7 +712,6 @@
         __annotate_shrink(__old_size);
     }
 
-#ifndef _LIBCPP_CXX03_LANG
     template <class _Up>
     _LIBCPP_INLINE_VISIBILITY
     inline void __push_back_slow_path(_Up&& __x);
@@ -735,11 +719,6 @@
     template <class... _Args>
     _LIBCPP_INLINE_VISIBILITY
     inline void __emplace_back_slow_path(_Args&&... __args);
-#else
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    inline void __push_back_slow_path(_Up& __x);
-#endif
 
     // The following functions are no-ops outside of AddressSanitizer mode.
     // We call annotatations only for the default Allocator because other allocators
@@ -1113,7 +1092,7 @@
 {
     _VSTD::__debug_db_insert_c(this);
     for (; __first != __last; ++__first)
-        __emplace_back(*__first);
+        emplace_back(*__first);
 }
 
 template <class _Tp, class _Allocator>
@@ -1128,7 +1107,7 @@
 {
     _VSTD::__debug_db_insert_c(this);
     for (; __first != __last; ++__first)
-        __emplace_back(*__first);
+        emplace_back(*__first);
 }
 
 template <class _Tp, class _Allocator>
@@ -1193,13 +1172,11 @@
     }
 }
 
-#ifndef _LIBCPP_CXX03_LANG
-
 template <class _Tp, class _Allocator>
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>::vector(vector&& __x)
 #if _LIBCPP_STD_VER > 14
-        _NOEXCEPT
+        noexcept
 #else
         _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
 #endif
@@ -1238,6 +1215,8 @@
     }
 }
 
+#ifndef _LIBCPP_CXX03_LANG
+
 template <class _Tp, class _Allocator>
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>::vector(initializer_list<value_type> __il)
@@ -1263,6 +1242,8 @@
     }
 }
 
+#endif // _LIBCPP_CXX03_LANG
+
 template <class _Tp, class _Allocator>
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>&
@@ -1304,8 +1285,6 @@
 #endif
 }
 
-#endif // !_LIBCPP_CXX03_LANG
-
 template <class _Tp, class _Allocator>
 inline _LIBCPP_INLINE_VISIBILITY
 vector<_Tp, _Allocator>&
@@ -1334,7 +1313,7 @@
 {
     clear();
     for (; __first != __last; ++__first)
-        __emplace_back(*__first);
+        emplace_back(*__first);
 }
 
 template <class _Tp, class _Allocator>
@@ -1528,11 +1507,7 @@
 template <class _Tp, class _Allocator>
 template <class _Up>
 void
-#ifndef _LIBCPP_CXX03_LANG
 vector<_Tp, _Allocator>::__push_back_slow_path(_Up&& __x)
-#else
-vector<_Tp, _Allocator>::__push_back_slow_path(_Up& __x)
-#endif
 {
     allocator_type& __a = this->__alloc();
     __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), size(), __a);
@@ -1555,8 +1530,6 @@
         __push_back_slow_path(__x);
 }
 
-#ifndef _LIBCPP_CXX03_LANG
-
 template <class _Tp, class _Allocator>
 inline _LIBCPP_INLINE_VISIBILITY
 void
@@ -1604,8 +1577,6 @@
 #endif
 }
 
-#endif // !_LIBCPP_CXX03_LANG
-
 template <class _Tp, class _Allocator>
 inline
 void
@@ -1702,8 +1673,6 @@
     return __make_iter(__p);
 }
 
-#ifndef _LIBCPP_CXX03_LANG
-
 template <class _Tp, class _Allocator>
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::insert(const_iterator __position, value_type&& __x)
@@ -1764,8 +1733,6 @@
     return __make_iter(__p);
 }
 
-#endif // !_LIBCPP_CXX03_LANG
-
 template <class _Tp, class _Allocator>
 typename vector<_Tp, _Allocator>::iterator
 vector<_Tp, _Allocator>::insert(const_iterator __position, size_type __n, const_reference __x)
@@ -2147,10 +2114,16 @@
     vector(initializer_list<value_type> __il);
     vector(initializer_list<value_type> __il, const allocator_type& __a);
 
+    _LIBCPP_INLINE_VISIBILITY
+    vector& operator=(initializer_list<value_type> __il)
+        {assign(__il.begin(), __il.end()); return *this;}
+
+#endif // !_LIBCPP_CXX03_LANG
+
     _LIBCPP_INLINE_VISIBILITY
     vector(vector&& __v)
 #if _LIBCPP_STD_VER > 14
-        _NOEXCEPT;
+        noexcept;
 #else
         _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
 #endif
@@ -2159,12 +2132,6 @@
     vector& operator=(vector&& __v)
         _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
 
-    _LIBCPP_INLINE_VISIBILITY
-    vector& operator=(initializer_list<value_type> __il)
-        {assign(__il.begin(), __il.end()); return *this;}
-
-#endif // !_LIBCPP_CXX03_LANG
-
     template <class _InputIterator>
         typename enable_if
         <
@@ -2769,8 +2736,6 @@
     return *this;
 }
 
-#ifndef _LIBCPP_CXX03_LANG
-
 template <class _Allocator>
 inline _LIBCPP_INLINE_VISIBILITY vector<bool, _Allocator>::vector(vector&& __v)
 #if _LIBCPP_STD_VER > 14
@@ -2842,8 +2807,6 @@
     __c.__cap() = __c.__size_ = 0;
 }
 
-#endif // !_LIBCPP_CXX03_LANG
-
 template <class _Allocator>
 void
 vector<bool, _Allocator>::assign(size_type __n, const value_type& __x)
diff --git a/libcxx/test/std/containers/sequences/vector/vector.cons/assign_move.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.cons/assign_move.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.cons/assign_move.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.cons/assign_move.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // vector& operator=(vector&& c);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.cons/copy.move_only.verify.cpp b/libcxx/test/std/containers/sequences/vector/vector.cons/copy.move_only.verify.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.cons/copy.move_only.verify.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.cons/copy.move_only.verify.cpp
@@ -8,8 +8,6 @@
 
 // Make sure that a std::vector containing move-only types can't be copied.
 
-// UNSUPPORTED: c++03
-
 #include <vector>
 
 struct move_only
diff --git a/libcxx/test/std/containers/sequences/vector/vector.cons/move.addressof.compile.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.cons/move.addressof.compile.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.cons/move.addressof.compile.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.cons/move.addressof.compile.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // vector(vector&& c);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.cons/move.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.cons/move.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.cons/move.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.cons/move.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // vector(vector&& c);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.cons/move_alloc.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.cons/move_alloc.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.cons/move_alloc.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.cons/move_alloc.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // vector(vector&& c, const allocator_type& a);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace.addressof.compile.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace.addressof.compile.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace.addressof.compile.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace.addressof.compile.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // template <class... Args> iterator emplace(const_iterator pos, Args&&... args);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // template <class... Args> iterator emplace(const_iterator pos, Args&&... args);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace_back.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace_back.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace_back.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace_back.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // template <class... Args> reference emplace_back(Args&&... args);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.modifiers/insert_iter_rvalue.addressof.compile.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.modifiers/insert_iter_rvalue.addressof.compile.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.modifiers/insert_iter_rvalue.addressof.compile.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.modifiers/insert_iter_rvalue.addressof.compile.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // iterator insert(const_iterator position, value_type&& x);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.modifiers/insert_iter_rvalue.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.modifiers/insert_iter_rvalue.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.modifiers/insert_iter_rvalue.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.modifiers/insert_iter_rvalue.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // iterator insert(const_iterator position, value_type&& x);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.modifiers/push_back_rvalue.pass.cpp b/libcxx/test/std/containers/sequences/vector/vector.modifiers/push_back_rvalue.pass.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.modifiers/push_back_rvalue.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.modifiers/push_back_rvalue.pass.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // void push_back(value_type&& x);
diff --git a/libcxx/test/std/containers/sequences/vector/vector.modifiers/resize_not_move_insertable.fail.cpp b/libcxx/test/std/containers/sequences/vector/vector.modifiers/resize_not_move_insertable.fail.cpp
--- a/libcxx/test/std/containers/sequences/vector/vector.modifiers/resize_not_move_insertable.fail.cpp
+++ b/libcxx/test/std/containers/sequences/vector/vector.modifiers/resize_not_move_insertable.fail.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03
-
 // <vector>
 
 // Test that vector produces a decent diagnostic for user types that explicitly