diff --git a/include/bitset b/include/bitset
index a2b8b58..aa2410e 100644
--- a/include/bitset
+++ b/include/bitset
@@ -27,19 +27,19 @@
     class reference
     {
         friend class bitset;
-        reference();
+        reference() noexcept;
     public:
-        ~reference();
-        reference& operator=(bool x);           // for b[i] = x;
-        reference& operator=(const reference&); // for b[i] = b[j];
-        bool operator~() const;                 // flips the bit
-        operator bool() const;                  // for x = b[i];
-        reference& flip();                      // for b[i].flip();
+        ~reference() noexcept;
+        reference& operator=(bool x) noexcept;           // for b[i] = x;
+        reference& operator=(const reference&) noexcept; // for b[i] = b[j];
+        bool operator~() const noexcept;                 // flips the bit
+        operator bool() const noexcept;                  // for x = b[i];
+        reference& flip() noexcept;                      // for b[i].flip();
     };
 
     // 23.3.5.1 constructors:
-    constexpr bitset();
-    constexpr bitset(unsigned long long val);
+    constexpr bitset() noexcept;
+    constexpr bitset(unsigned long long val) noexcept;
     template <class charT>
         explicit bitset(const charT* str,
                         typename basic_string<charT>::size_type n = basic_string<charT>::npos,
@@ -52,17 +52,17 @@
                         charT zero = charT('0'), charT one = charT('1'));
 
     // 23.3.5.2 bitset operations:
-    bitset& operator&=(const bitset& rhs);
-    bitset& operator|=(const bitset& rhs);
-    bitset& operator^=(const bitset& rhs);
-    bitset& operator<<=(size_t pos);
-    bitset& operator>>=(size_t pos);
-    bitset& set();
+    bitset& operator&=(const bitset& rhs) noexcept;
+    bitset& operator|=(const bitset& rhs) noexcept;
+    bitset& operator^=(const bitset& rhs) noexcept;
+    bitset& operator<<=(size_t pos) noexcept;
+    bitset& operator>>=(size_t pos) noexcept;
+    bitset& set() noexcept;
     bitset& set(size_t pos, bool val = true);
-    bitset& reset();
+    bitset& reset() noexcept;
     bitset& reset(size_t pos);
-    bitset operator~() const;
-    bitset& flip();
+    bitset operator~() const noexcept;
+    bitset& flip() noexcept;
     bitset& flip(size_t pos);
 
     // element access:
@@ -77,27 +77,27 @@
     template <class charT>
         basic_string<charT, char_traits<charT>, allocator<charT> > to_string(charT zero = charT('0'), charT one = charT('1')) const;
     basic_string<char, char_traits<char>, allocator<char> > to_string(char zero = '0', char one = '1') const;
-    size_t count() const;
-    constexpr size_t size() const;
-    bool operator==(const bitset& rhs) const;
-    bool operator!=(const bitset& rhs) const;
+    size_t count() const noexcept;
+    constexpr size_t size() const noexcept;
+    bool operator==(const bitset& rhs) const noexcept;
+    bool operator!=(const bitset& rhs) const noexcept;
     bool test(size_t pos) const;
-    bool all() const;
-    bool any() const;
-    bool none() const;
-    bitset operator<<(size_t pos) const;
-    bitset operator>>(size_t pos) const;
+    bool all() const noexcept;
+    bool any() const noexcept;
+    bool none() const noexcept;
+    bitset operator<<(size_t pos) const noexcept;
+    bitset operator>>(size_t pos) const noexcept;
 };
 
 // 23.3.5.3 bitset operators:
 template <size_t N>
-bitset<N> operator&(const bitset<N>&, const bitset<N>&);
+bitset<N> operator&(const bitset<N>&, const bitset<N>&) noexcept;
 
 template <size_t N>
-bitset<N> operator|(const bitset<N>&, const bitset<N>&);
+bitset<N> operator|(const bitset<N>&, const bitset<N>&) noexcept;
 
 template <size_t N>
-bitset<N> operator^(const bitset<N>&, const bitset<N>&);
+bitset<N> operator^(const bitset<N>&, const bitset<N>&) noexcept;
 
 template <class charT, class traits, size_t N>
 basic_istream<charT, traits>&
@@ -155,34 +155,34 @@
     typedef __bit_iterator<__bitset, false>            iterator;
     typedef __bit_iterator<__bitset, true>             const_iterator;
 
-    __bitset();
-    explicit __bitset(unsigned long long __v);
+    __bitset() _NOEXCEPT;
+    explicit __bitset(unsigned long long __v) _NOEXCEPT;
 
-    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t __pos)
+    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t __pos) _NOEXCEPT
         {return reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY const_reference __make_ref(size_t __pos) const
+    _LIBCPP_INLINE_VISIBILITY const_reference __make_ref(size_t __pos) const _NOEXCEPT
         {return const_reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos)
+    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos) _NOEXCEPT
         {return iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const
+    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const _NOEXCEPT
         {return const_iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
 
-    void operator&=(const __bitset& __v);
-    void operator|=(const __bitset& __v);
-    void operator^=(const __bitset& __v);
+    void operator&=(const __bitset& __v) _NOEXCEPT;
+    void operator|=(const __bitset& __v) _NOEXCEPT;
+    void operator^=(const __bitset& __v) _NOEXCEPT;
 
-    void flip();
+    void flip() _NOEXCEPT;
     _LIBCPP_INLINE_VISIBILITY unsigned long to_ulong() const
         {return to_ulong(integral_constant<bool, _Size < sizeof(unsigned long) * CHAR_BIT>());}
     _LIBCPP_INLINE_VISIBILITY unsigned long long to_ullong() const
         {return to_ullong(integral_constant<bool, _Size < sizeof(unsigned long long) * CHAR_BIT>());}
 
-    bool all() const;
-    bool any() const;
-    size_t __hash_code() const;
+    bool all() const _NOEXCEPT;
+    bool any() const _NOEXCEPT;
+    size_t __hash_code() const _NOEXCEPT;
 private:
-    void __init(unsigned long long __v, false_type);
-    void __init(unsigned long long __v, true_type);
+    void __init(unsigned long long __v, false_type) _NOEXCEPT;
+    void __init(unsigned long long __v, true_type) _NOEXCEPT;
     unsigned long to_ulong(false_type) const;
     unsigned long to_ulong(true_type) const;
     unsigned long long to_ullong(false_type) const;
@@ -193,7 +193,7 @@
 
 template <size_t _N_words, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-__bitset<_N_words, _Size>::__bitset()
+__bitset<_N_words, _Size>::__bitset() _NOEXCEPT
 {
     _STD::fill_n(__first_, _N_words, __storage_type(0));
 }
@@ -221,7 +221,7 @@
 
 template <size_t _N_words, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-__bitset<_N_words, _Size>::__bitset(unsigned long long __v)
+__bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
 {
     __init(__v, integral_constant<bool, sizeof(unsigned long long) == sizeof(__storage_type)>());
 }
@@ -229,7 +229,7 @@
 template <size_t _N_words, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 void
-__bitset<_N_words, _Size>::operator&=(const __bitset& __v)
+__bitset<_N_words, _Size>::operator&=(const __bitset& __v) _NOEXCEPT
 {
     for (size_type __i = 0; __i < _N_words; ++__i)
         __first_[__i] &= __v.__first_[__i];
@@ -238,7 +238,7 @@
 template <size_t _N_words, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 void
-__bitset<_N_words, _Size>::operator|=(const __bitset& __v)
+__bitset<_N_words, _Size>::operator|=(const __bitset& __v) _NOEXCEPT
 {
     for (size_type __i = 0; __i < _N_words; ++__i)
         __first_[__i] |= __v.__first_[__i];
@@ -247,7 +247,7 @@
 template <size_t _N_words, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 void
-__bitset<_N_words, _Size>::operator^=(const __bitset& __v)
+__bitset<_N_words, _Size>::operator^=(const __bitset& __v) _NOEXCEPT
 {
     for (size_type __i = 0; __i < _N_words; ++__i)
         __first_[__i] ^= __v.__first_[__i];
@@ -255,7 +255,7 @@
 
 template <size_t _N_words, size_t _Size>
 void
-__bitset<_N_words, _Size>::flip()
+__bitset<_N_words, _Size>::flip() _NOEXCEPT
 {
     // do middle whole words
     size_type __n = _Size;
@@ -338,7 +338,7 @@
 
 template <size_t _N_words, size_t _Size>
 bool
-__bitset<_N_words, _Size>::all() const
+__bitset<_N_words, _Size>::all() const _NOEXCEPT
 {
     // do middle whole words
     size_type __n = _Size;
@@ -358,7 +358,7 @@
 
 template <size_t _N_words, size_t _Size>
 bool
-__bitset<_N_words, _Size>::any() const
+__bitset<_N_words, _Size>::any() const _NOEXCEPT
 {
     // do middle whole words
     size_type __n = _Size;
@@ -379,7 +379,7 @@
 template <size_t _N_words, size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 size_t
-__bitset<_N_words, _Size>::__hash_code() const
+__bitset<_N_words, _Size>::__hash_code() const _NOEXCEPT
 {
     size_t __h = 0;
     for (size_type __i = 0; __i < _N_words; ++__i)
@@ -413,43 +413,43 @@
     typedef __bit_iterator<__bitset, false>            iterator;
     typedef __bit_iterator<__bitset, true>             const_iterator;
 
-    __bitset();
-    explicit __bitset(unsigned long long __v);
+    __bitset() _NOEXCEPT;
+    explicit __bitset(unsigned long long __v) _NOEXCEPT;
 
-    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t __pos)
+    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t __pos) _NOEXCEPT
         {return reference(&__first_, __storage_type(1) << __pos);}
-    _LIBCPP_INLINE_VISIBILITY const_reference __make_ref(size_t __pos) const
+    _LIBCPP_INLINE_VISIBILITY const_reference __make_ref(size_t __pos) const _NOEXCEPT
         {return const_reference(&__first_, __storage_type(1) << __pos);}
-    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos)
+    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos) _NOEXCEPT
         {return iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const
+    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const _NOEXCEPT
         {return const_iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
 
-    void operator&=(const __bitset& __v);
-    void operator|=(const __bitset& __v);
-    void operator^=(const __bitset& __v);
+    void operator&=(const __bitset& __v) _NOEXCEPT;
+    void operator|=(const __bitset& __v) _NOEXCEPT;
+    void operator^=(const __bitset& __v) _NOEXCEPT;
 
-    void flip();
+    void flip() _NOEXCEPT;
 
     unsigned long to_ulong() const;
     unsigned long long to_ullong() const;
 
-    bool all() const;
-    bool any() const;
+    bool all() const _NOEXCEPT;
+    bool any() const _NOEXCEPT;
 
-    size_t __hash_code() const;
+    size_t __hash_code() const _NOEXCEPT;
 };
 
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-__bitset<1, _Size>::__bitset()
+__bitset<1, _Size>::__bitset() _NOEXCEPT
     : __first_(0)
 {
 }
 
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
-__bitset<1, _Size>::__bitset(unsigned long long __v)
+__bitset<1, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
     : __first_(static_cast<__storage_type>(__v))
 {
 }
@@ -457,7 +457,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 void
-__bitset<1, _Size>::operator&=(const __bitset& __v)
+__bitset<1, _Size>::operator&=(const __bitset& __v) _NOEXCEPT
 {
     __first_ &= __v.__first_;
 }
@@ -465,7 +465,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 void
-__bitset<1, _Size>::operator|=(const __bitset& __v)
+__bitset<1, _Size>::operator|=(const __bitset& __v) _NOEXCEPT
 {
     __first_ |= __v.__first_;
 }
@@ -473,7 +473,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 void
-__bitset<1, _Size>::operator^=(const __bitset& __v)
+__bitset<1, _Size>::operator^=(const __bitset& __v) _NOEXCEPT
 {
     __first_ ^= __v.__first_;
 }
@@ -481,7 +481,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 void
-__bitset<1, _Size>::flip()
+__bitset<1, _Size>::flip() _NOEXCEPT
 {
     __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
     __first_ = ~__first_;
@@ -507,7 +507,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bool
-__bitset<1, _Size>::all() const
+__bitset<1, _Size>::all() const _NOEXCEPT
 {
     __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
     return !(~__first_ & __m);
@@ -516,7 +516,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bool
-__bitset<1, _Size>::any() const
+__bitset<1, _Size>::any() const _NOEXCEPT
 {
     __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
     return __first_ & __m;
@@ -525,7 +525,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 size_t
-__bitset<1, _Size>::__hash_code() const
+__bitset<1, _Size>::__hash_code() const _NOEXCEPT
 {
     return __first_;
 }
@@ -554,40 +554,40 @@
     typedef __bit_iterator<__bitset, false>            iterator;
     typedef __bit_iterator<__bitset, true>             const_iterator;
 
-    __bitset();
-    explicit __bitset(unsigned long long);
+    __bitset() _NOEXCEPT;
+    explicit __bitset(unsigned long long) _NOEXCEPT;
 
-    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t)
+    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t) _NOEXCEPT
         {return reference(0, 1);}
-    _LIBCPP_INLINE_VISIBILITY const_reference __make_ref(size_t) const
+    _LIBCPP_INLINE_VISIBILITY const_reference __make_ref(size_t) const _NOEXCEPT
         {return const_reference(0, 1);}
-    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos)
+    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos) _NOEXCEPT
         {return iterator(0, 0);}
-    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const
+    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const _NOEXCEPT
         {return const_iterator(0, 0);}
 
-    _LIBCPP_INLINE_VISIBILITY void operator&=(const __bitset&) {}
-    _LIBCPP_INLINE_VISIBILITY void operator|=(const __bitset&) {}
-    _LIBCPP_INLINE_VISIBILITY void operator^=(const __bitset&) {}
+    _LIBCPP_INLINE_VISIBILITY void operator&=(const __bitset&) _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY void operator|=(const __bitset&) _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY void operator^=(const __bitset&) _NOEXCEPT {}
 
-    _LIBCPP_INLINE_VISIBILITY void flip() {}
+    _LIBCPP_INLINE_VISIBILITY void flip() _NOEXCEPT {}
 
     _LIBCPP_INLINE_VISIBILITY unsigned long to_ulong() const {return 0;}
     _LIBCPP_INLINE_VISIBILITY unsigned long long to_ullong() const {return 0;}
 
-    _LIBCPP_INLINE_VISIBILITY bool all() const {return true;}
-    _LIBCPP_INLINE_VISIBILITY bool any() const {return false;}
+    _LIBCPP_INLINE_VISIBILITY bool all() const _NOEXCEPT {return true;}
+    _LIBCPP_INLINE_VISIBILITY bool any() const _NOEXCEPT {return false;}
 
-    _LIBCPP_INLINE_VISIBILITY size_t __hash_code() const {return 0;}
+    _LIBCPP_INLINE_VISIBILITY size_t __hash_code() const _NOEXCEPT {return 0;}
 };
 
 inline _LIBCPP_INLINE_VISIBILITY
-__bitset<0, 0>::__bitset()
+__bitset<0, 0>::__bitset() _NOEXCEPT
 {
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
-__bitset<0, 0>::__bitset(unsigned long long)
+__bitset<0, 0>::__bitset(unsigned long long) _NOEXCEPT
 {
 }
 
@@ -606,8 +606,8 @@
     typedef typename base::const_reference const_reference;
 
     // 23.3.5.1 constructors:
-    /*constexpr*/ _LIBCPP_INLINE_VISIBILITY bitset() {}
-    /*constexpr*/ _LIBCPP_INLINE_VISIBILITY bitset(unsigned long long __v) : base(__v) {}
+    /*constexpr*/ _LIBCPP_INLINE_VISIBILITY bitset() _NOEXCEPT {}
+    /*constexpr*/ _LIBCPP_INLINE_VISIBILITY bitset(unsigned long long __v) _NOEXCEPT : base(__v) {}
     template<class _CharT>
         explicit bitset(const _CharT* __str,
                         typename basic_string<_CharT>::size_type __n = basic_string<_CharT>::npos,
@@ -620,17 +620,17 @@
                         _CharT __zero = _CharT('0'), _CharT __one = _CharT('1'));
 
     // 23.3.5.2 bitset operations:
-    bitset& operator&=(const bitset& __rhs);
-    bitset& operator|=(const bitset& __rhs);
-    bitset& operator^=(const bitset& __rhs);
-    bitset& operator<<=(size_t __pos);
-    bitset& operator>>=(size_t __pos);
-    bitset& set();
+    bitset& operator&=(const bitset& __rhs) _NOEXCEPT;
+    bitset& operator|=(const bitset& __rhs) _NOEXCEPT;
+    bitset& operator^=(const bitset& __rhs) _NOEXCEPT;
+    bitset& operator<<=(size_t __pos) _NOEXCEPT;
+    bitset& operator>>=(size_t __pos) _NOEXCEPT;
+    bitset& set() _NOEXCEPT;
     bitset& set(size_t __pos, bool __val = true);
-    bitset& reset();
+    bitset& reset() _NOEXCEPT;
     bitset& reset(size_t __pos);
-    bitset  operator~() const;
-    bitset& flip();
+    bitset  operator~() const _NOEXCEPT;
+    bitset& flip() _NOEXCEPT;
     bitset& flip(size_t __pos);
 
     // element access:
@@ -649,21 +649,21 @@
                                                                                 _CharT __one = _CharT('1')) const;
     basic_string<char, char_traits<char>, allocator<char> > to_string(char __zero = '0',
                                                                       char __one = '1') const;
-    size_t count() const;
-    /*constexpr*/ _LIBCPP_INLINE_VISIBILITY size_t size() const {return _Size;}
-    bool operator==(const bitset& __rhs) const;
-    bool operator!=(const bitset& __rhs) const;
+    size_t count() const _NOEXCEPT;
+    /*constexpr*/ _LIBCPP_INLINE_VISIBILITY size_t size() const _NOEXCEPT {return _Size;}
+    bool operator==(const bitset& __rhs) const _NOEXCEPT;
+    bool operator!=(const bitset& __rhs) const _NOEXCEPT;
     bool test(size_t __pos) const;
-    bool all() const;
-    bool any() const;
-    _LIBCPP_INLINE_VISIBILITY bool none() const {return !any();}
-    bitset operator<<(size_t __pos) const;
-    bitset operator>>(size_t __pos) const;
+    bool all() const _NOEXCEPT;
+    bool any() const _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY bool none() const _NOEXCEPT {return !any();}
+    bitset operator<<(size_t __pos) const _NOEXCEPT;
+    bitset operator>>(size_t __pos) const _NOEXCEPT;
 
 private:
 
     _LIBCPP_INLINE_VISIBILITY
-    size_t __hash_code() const {return base::__hash_code();}
+    size_t __hash_code() const _NOEXCEPT {return base::__hash_code();}
 
     friend struct hash<bitset>;
 };
@@ -732,7 +732,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>&
-bitset<_Size>::operator&=(const bitset& __rhs)
+bitset<_Size>::operator&=(const bitset& __rhs) _NOEXCEPT
 {
     base::operator&=(__rhs);
     return *this;
@@ -741,7 +741,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>&
-bitset<_Size>::operator|=(const bitset& __rhs)
+bitset<_Size>::operator|=(const bitset& __rhs) _NOEXCEPT
 {
     base::operator|=(__rhs);
     return *this;
@@ -750,7 +750,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>&
-bitset<_Size>::operator^=(const bitset& __rhs)
+bitset<_Size>::operator^=(const bitset& __rhs) _NOEXCEPT
 {
     base::operator^=(__rhs);
     return *this;
@@ -758,7 +758,7 @@
 
 template <size_t _Size>
 bitset<_Size>&
-bitset<_Size>::operator<<=(size_t __pos)
+bitset<_Size>::operator<<=(size_t __pos) _NOEXCEPT
 {
     __pos = _STD::min(__pos, _Size);
     _STD::copy_backward(base::__make_iter(0), base::__make_iter(_Size - __pos), base::__make_iter(_Size));
@@ -768,7 +768,7 @@
 
 template <size_t _Size>
 bitset<_Size>&
-bitset<_Size>::operator>>=(size_t __pos)
+bitset<_Size>::operator>>=(size_t __pos) _NOEXCEPT
 {
     __pos = _STD::min(__pos, _Size);
     _STD::copy(base::__make_iter(__pos), base::__make_iter(_Size), base::__make_iter(0));
@@ -779,7 +779,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>&
-bitset<_Size>::set()
+bitset<_Size>::set() _NOEXCEPT
 {
     _STD::fill_n(base::__make_iter(0), _Size, true);
     return *this;
@@ -802,7 +802,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>&
-bitset<_Size>::reset()
+bitset<_Size>::reset() _NOEXCEPT
 {
     _STD::fill_n(base::__make_iter(0), _Size, false);
     return *this;
@@ -825,7 +825,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>
-bitset<_Size>::operator~() const
+bitset<_Size>::operator~() const _NOEXCEPT
 {
     bitset __x(*this);
     __x.flip();
@@ -835,7 +835,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>&
-bitset<_Size>::flip()
+bitset<_Size>::flip() _NOEXCEPT
 {
     base::flip();
     return *this;
@@ -915,7 +915,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 size_t
-bitset<_Size>::count() const
+bitset<_Size>::count() const _NOEXCEPT
 {
     return static_cast<size_t>(_STD::count(base::__make_iter(0), base::__make_iter(_Size), true));
 }
@@ -923,7 +923,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bool
-bitset<_Size>::operator==(const bitset& __rhs) const
+bitset<_Size>::operator==(const bitset& __rhs) const _NOEXCEPT
 {
     return _STD::equal(base::__make_iter(0), base::__make_iter(_Size), __rhs.__make_iter(0));
 }
@@ -931,7 +931,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bool
-bitset<_Size>::operator!=(const bitset& __rhs) const
+bitset<_Size>::operator!=(const bitset& __rhs) const _NOEXCEPT
 {
     return !(*this == __rhs);
 }
@@ -952,7 +952,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bool
-bitset<_Size>::all() const
+bitset<_Size>::all() const _NOEXCEPT
 {
     return base::all();
 }
@@ -960,7 +960,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bool
-bitset<_Size>::any() const
+bitset<_Size>::any() const _NOEXCEPT
 {
     return base::any();
 }
@@ -968,7 +968,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>
-bitset<_Size>::operator<<(size_t __pos) const
+bitset<_Size>::operator<<(size_t __pos) const _NOEXCEPT
 {
     bitset __r = *this;
     __r <<= __pos;
@@ -978,7 +978,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>
-bitset<_Size>::operator>>(size_t __pos) const
+bitset<_Size>::operator>>(size_t __pos) const _NOEXCEPT
 {
     bitset __r = *this;
     __r >>= __pos;
@@ -988,7 +988,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>
-operator&(const bitset<_Size>& __x, const bitset<_Size>& __y)
+operator&(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
 {
     bitset<_Size> __r = __x;
     __r &= __y;
@@ -998,7 +998,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>
-operator|(const bitset<_Size>& __x, const bitset<_Size>& __y)
+operator|(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
 {
     bitset<_Size> __r = __x;
     __r |= __y;
@@ -1008,7 +1008,7 @@
 template <size_t _Size>
 inline _LIBCPP_INLINE_VISIBILITY
 bitset<_Size>
-operator^(const bitset<_Size>& __x, const bitset<_Size>& __y)
+operator^(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
 {
     bitset<_Size> __r = __x;
     __r ^= __y;
@@ -1020,7 +1020,7 @@
     : public unary_function<bitset<_Size>, size_t>
 {
     _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const bitset<_Size>& __bs) const
+    size_t operator()(const bitset<_Size>& __bs) const _NOEXCEPT
         {return __bs.__hash_code();}
 };