I've become quite disatsified with the lack of noexcept specifications on container move construction, move assignment operator and swap. Without proper decoration on at least move construction, vectors of containers will have unacceptable performance. Here's the fix for deque. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@132480 91177308-0d34-0410-b5e6-96231b3b80d8 
diff --git a/include/deque b/include/deque index 2063bd8..1ffd9d8 100644 --- a/include/deque +++ b/include/deque 
@@ -930,21 +930,29 @@    __deque_base();  explicit __deque_base(const allocator_type& __a); +public:  ~__deque_base();    #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES   - __deque_base(__deque_base&& __c); + __deque_base(__deque_base&& __c) + _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);  __deque_base(__deque_base&& __c, const allocator_type& __a);    #endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES - void swap(__deque_base& __c); + void swap(__deque_base& __c) + _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value|| + __is_nothrow_swappable<allocator_type>::value); +protected:  void clear() _NOEXCEPT;    bool __invariants() const;    _LIBCPP_INLINE_VISIBILITY  void __move_assign(__deque_base& __c) + _NOEXCEPT_(is_nothrow_move_assignable<__map>::value && + (!__alloc_traits::propagate_on_container_move_assignment::value || + is_nothrow_move_assignable<allocator_type>::value))  {  __map_ = _STD::move(__c.__map_);  __start_ = __c.__start_; @@ -955,27 +963,33 @@    _LIBCPP_INLINE_VISIBILITY  void __move_assign_alloc(__deque_base& __c) + _NOEXCEPT_(!__alloc_traits::propagate_on_container_move_assignment::value || + is_nothrow_move_assignable<allocator_type>::value)  {__move_assign_alloc(__c, integral_constant<bool,  __alloc_traits::propagate_on_container_move_assignment::value>());}    private:  _LIBCPP_INLINE_VISIBILITY  void __move_assign_alloc(const __deque_base& __c, true_type) + _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)  {  __alloc() = _STD::move(__c.__alloc());  }    _LIBCPP_INLINE_VISIBILITY - void __move_assign_alloc(const __deque_base& __c, false_type) + void __move_assign_alloc(const __deque_base& __c, false_type) _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 _STD::swap;  swap(__x, __y); @@ -983,6 +997,7 @@    _LIBCPP_INLINE_VISIBILITY  static void __swap_alloc(allocator_type& __x, allocator_type& __y, false_type) + _NOEXCEPT  {}  };   @@ -1073,6 +1088,7 @@    template <class _Tp, class _Allocator>  __deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c) + _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)  : __map_(_STD::move(__c.__map_)),  __start_(_STD::move(__c.__start_)),  __size_(_STD::move(__c.__size_)) @@ -1105,6 +1121,8 @@  template <class _Tp, class _Allocator>  void  __deque_base<_Tp, _Allocator>::swap(__deque_base& __c) + _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value|| + __is_nothrow_swappable<allocator_type>::value)  {  __map_.swap(__c.__map_);  _STD::swap(__start_, __c.__start_); @@ -1183,9 +1201,14 @@  deque& operator=(initializer_list<value_type> __il) {assign(__il); return *this;}    #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES - deque(deque&& __c); + deque(deque&& __c) _NOEXCEPT_(is_nothrow_move_constructible<__base>::value);  deque(deque&& __c, const allocator_type& __a); - deque& operator=(deque&& __c); + deque& operator=(deque&& __c) + _NOEXCEPT_( + (__alloc_traits::propagate_on_container_move_assignment::value && + is_nothrow_move_assignable<allocator_type>::value) || + (!__alloc_traits::propagate_on_container_move_assignment::value &&  + is_nothrow_move_assignable<value_type>::value));  #endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES    template <class _InputIter> @@ -1290,7 +1313,9 @@  iterator erase(const_iterator __p);  iterator erase(const_iterator __f, const_iterator __l);   - void swap(deque& __c); + void swap(deque& __c) + _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || + __is_nothrow_swappable<allocator_type>::value);  void clear() _NOEXCEPT;    _LIBCPP_INLINE_VISIBILITY @@ -1448,6 +1473,7 @@  template <class _Tp, class _Allocator>  inline _LIBCPP_INLINE_VISIBILITY  deque<_Tp, _Allocator>::deque(deque&& __c) + _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)  : __base(_STD::move(__c))  {  } @@ -1468,6 +1494,11 @@  inline _LIBCPP_INLINE_VISIBILITY  deque<_Tp, _Allocator>&  deque<_Tp, _Allocator>::operator=(deque&& __c) + _NOEXCEPT_( + (__alloc_traits::propagate_on_container_move_assignment::value && + is_nothrow_move_assignable<allocator_type>::value) || + (!__alloc_traits::propagate_on_container_move_assignment::value &&  + is_nothrow_move_assignable<value_type>::value))  {  __move_assign(__c, integral_constant<bool,  __alloc_traits::propagate_on_container_move_assignment::value>()); @@ -2713,6 +2744,8 @@  inline _LIBCPP_INLINE_VISIBILITY  void  deque<_Tp, _Allocator>::swap(deque& __c) + _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || + __is_nothrow_swappable<allocator_type>::value)  {  __base::swap(__c);  } @@ -2778,6 +2811,7 @@  _LIBCPP_INLINE_VISIBILITY inline  void  swap(deque<_Tp, _Allocator>& __x, deque<_Tp, _Allocator>& __y) + _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))  {  __x.swap(__y);  }