bitset

c++ STL source code, hash and vector etc

    return __result;
  }

  unsigned long _M_do_to_ulong() const { return _M_w; }

  size_t _M_do_find_first(size_t __not_found) const;

  // find the next "on" bit that follows "prev"
  size_t _M_do_find_next(size_t __prev, size_t __not_found) const; 

};

//
// Definitions of non-inline functions from the single-word version of
//  _Base_bitset.
//

size_t _Base_bitset<1>::_M_do_find_first(size_t __not_found) const
{
  _WordT __thisword = _M_w;

  if ( __thisword != static_cast<_WordT>(0) ) {
    // find byte within word
    for ( size_t __j = 0; __j < sizeof(_WordT); __j++ ) {
      unsigned char __this_byte
        = static_cast<unsigned char>(__thisword & (~(unsigned char)0));
      if ( __this_byte )
        return __j*CHAR_BIT + _First_one<true>::_S_first_one[__this_byte];

      __thisword >>= CHAR_BIT;
    }
  }
  // not found, so return a value that indicates failure.
  return __not_found;
}

size_t _Base_bitset<1>::_M_do_find_next(size_t __prev, size_t __not_found ) const
{
  // make bound inclusive
  ++__prev;

  // check out of bounds
  if ( __prev >= __BITS_PER_WORD )
    return __not_found;

    // search first (and only) word
  _WordT __thisword = _M_w;

  // mask off bits below bound
  __thisword &= (~static_cast<_WordT>(0)) << _S_whichbit(__prev);

  if ( __thisword != static_cast<_WordT>(0) ) {
    // find byte within word
    // get first byte into place
    __thisword >>= _S_whichbyte(__prev) * CHAR_BIT;
    for ( size_t __j = _S_whichbyte(__prev); __j < sizeof(_WordT); __j++ ) {
      unsigned char __this_byte
        = static_cast<unsigned char>(__thisword & (~(unsigned char)0));
      if ( __this_byte )
        return __j*CHAR_BIT + _First_one<true>::_S_first_one[__this_byte];

      __thisword >>= CHAR_BIT;
    }
  }

  // not found, so return a value that indicates failure.
  return __not_found;
} // end _M_do_find_next


// ------------------------------------------------------------
// Helper class to zero out the unused high-order bits in the highest word.

template <size_t _Extrabits> struct _Sanitize {
  static void _M_do_sanitize(unsigned long& __val)
    { __val &= ~((~static_cast<unsigned long>(0)) << _Extrabits); }
};

__STL_TEMPLATE_NULL struct _Sanitize<0> {
  static void _M_do_sanitize(unsigned long) {}
};



// ------------------------------------------------------------
// Class bitset.
//   _Nb may be any nonzero number of type size_t.

template<size_t _Nb>
class bitset : private _Base_bitset<__BITSET_WORDS(_Nb)>
{
private:
  typedef _Base_bitset<__BITSET_WORDS(_Nb)> _Base;
  typedef unsigned long _WordT;

private:
  void _M_do_sanitize() {
    _Sanitize<_Nb%__BITS_PER_WORD>::_M_do_sanitize(this->_M_hiword());
  }

public:

  // bit reference:
  class reference;
  friend class reference;

  class reference {
    friend class bitset;

    _WordT *_M_wp;
    size_t _M_bpos;

    // left undefined
    reference();

  public:
    reference( bitset& __b, size_t __pos ) {
      _M_wp = &__b._M_getword(__pos);
      _M_bpos = _Base::_S_whichbit(__pos);
    }

    ~reference() {}

    // for b[i] = __x;
    reference& operator=(bool __x) {
      if ( __x )
        *_M_wp |= _Base::_S_maskbit(_M_bpos);
      else
        *_M_wp &= ~_Base::_S_maskbit(_M_bpos);

      return *this;
    }

    // for b[i] = b[__j];
    reference& operator=(const reference& __j) {
      if ( (*(__j._M_wp) & _Base::_S_maskbit(__j._M_bpos)) )
        *_M_wp |= _Base::_S_maskbit(_M_bpos);
      else
        *_M_wp &= ~_Base::_S_maskbit(_M_bpos);

      return *this;
    }

    // flips the bit
    bool operator~() const
      { return (*(_M_wp) & _Base::_S_maskbit(_M_bpos)) == 0; }

    // for __x = b[i];
    operator bool() const
      { return (*(_M_wp) & _Base::_S_maskbit(_M_bpos)) != 0; }

    // for b[i].flip();
    reference& flip() {
      *_M_wp ^= _Base::_S_maskbit(_M_bpos);
      return *this;
    }
  };

  // 23.3.5.1 constructors:
  bitset() {}
  bitset(unsigned long __val) : _Base_bitset<__BITSET_WORDS(_Nb)>(__val) 
    { _M_do_sanitize(); }

#ifdef __STL_MEMBER_TEMPLATES
  template<class _CharT, class _Traits, class _Alloc>
  explicit bitset(const basic_string<_CharT, _Traits, _Alloc>& __s,
                  size_t __pos = 0)
    : _Base() 
  {
    if (__pos > __s.size()) 
      __STL_THROW(out_of_range("bitset"));
    _M_copy_from_string(__s, __pos,
                        basic_string<_CharT, _Traits, _Alloc>::npos);
  }
  template<class _CharT, class _Traits, class _Alloc>
  bitset(const basic_string<_CharT, _Traits, _Alloc>& __s,
         size_t __pos,
         size_t __n)
    : _Base() 
  {
    if (__pos > __s.size()) 
      __STL_THROW(out_of_range("bitset"));
    _M_copy_from_string(__s, __pos, __n);
  }
#else /* __STL_MEMBER_TEMPLATES */
  explicit bitset(const basic_string<char>& __s,
                  size_t __pos = 0,
                  size_t __n = basic_string<char>::npos) 
    : _Base() 
  {
    if (__pos > __s.size()) 
      __STL_THROW(out_of_range("bitset"));
    _M_copy_from_string(__s, __pos, __n);
  }
#endif /* __STL_MEMBER_TEMPLATES */

  // 23.3.5.2 bitset operations:
  bitset<_Nb>& operator&=(const bitset<_Nb>& __rhs) {
    this->_M_do_and(__rhs);
    return *this;
  }

  bitset<_Nb>& operator|=(const bitset<_Nb>& __rhs) {
    this->_M_do_or(__rhs);
    return *this;
  }

  bitset<_Nb>& operator^=(const bitset<_Nb>& __rhs) {
    this->_M_do_xor(__rhs);
    return *this;
  }

  bitset<_Nb>& operator<<=(size_t __pos) {
    this->_M_do_left_shift(__pos);
    this->_M_do_sanitize();
    return *this;
  }

  bitset<_Nb>& operator>>=(size_t __pos) {
    this->_M_do_right_shift(__pos);
    this->_M_do_sanitize();
    return *this;
  }

  //
  // Extension:
  // Versions of single-bit set, reset, flip, test with no range checking.
  //

  bitset<_Nb>& _Unchecked_set(size_t __pos) {
    this->_M_getword(__pos) |= _Base::_S_maskbit(__pos);
    return *this;
  }

  bitset<_Nb>& _Unchecked_set(size_t __pos, int __val) {
    if (__val)
      this->_M_getword(__pos) |= _Base::_S_maskbit(__pos);
    else
      this->_M_getword(__pos) &= ~_Base::_S_maskbit(__pos);

    return *this;
  }

  bitset<_Nb>& _Unchecked_reset(size_t __pos) {
    this->_M_getword(__pos) &= ~_Base::_S_maskbit(__pos);
    return *this;
  }

  bitset<_Nb>& _Unchecked_flip(size_t __pos) {
    this->_M_getword(__pos) ^= _Base::_S_maskbit(__pos);
    return *this;
  }

  bool _Unchecked_test(size_t __pos) const {
    return (this->_M_getword(__pos) & _Base::_S_maskbit(__pos))
      != static_cast<_WordT>(0);
  }

  // Set, reset, and flip.

  bitset<_Nb>& set() {
    this->_M_do_set();
    this->_M_do_sanitize();
    return *this;
  }

  bitset<_Nb>& set(size_t __pos) {
    if (__pos >= _Nb)
      __STL_THROW(out_of_range("bitset"));

    return _Unchecked_set(__pos);
  }

  bitset<_Nb>& set(size_t __pos, int __val) {
    if (__pos >= _Nb)
      __STL_THROW(out_of_range("bitset"));

    return _Unchecked_set(__pos, __val);
  }

  bitset<_Nb>& reset() {
    this->_M_do_reset();
    return *this;
  }

  bitset<_Nb>& reset(size_t __pos) {
    if (__pos >= _Nb)
      __STL_THROW(out_of_range("bitset"));

    return _Unchecked_reset(__pos);
  }

  bitset<_Nb>& flip() {
    this->_M_do_flip();
    this->_M_do_sanitize();
    return *this;
  }

  bitset<_Nb>& flip(size_t __pos) {
    if (__pos >= _Nb)
      __STL_THROW(out_of_range("bitset"));

    return _Unchecked_flip(__pos);
  }

  bitset<_Nb> operator~() const { 
    return bitset<_Nb>(*this).flip();
  }

  // element access:
  //for b[i];
  reference operator[](size_t __pos) { return reference(*this,__pos); }
  bool operator[](size_t __pos) const { return _Unchecked_test(__pos); }

  unsigned long to_ulong() const { return this->_M_do_to_ulong(); }

#if defined(__STL_MEMBER_TEMPLATES) && \
    defined(__STL_EXPLICIT_FUNCTION_TMPL_ARGS)
  template <class _CharT, class _Traits, class _Alloc>
  basic_string<_CharT, _Traits, _Alloc> to_string() const {
    basic_string<_CharT, _Traits, _Alloc> __result;
    _M_copy_to_string(__result);
    return __result;
  }
#endif /* member templates and explicit function template args */

  // Helper functions for string operations.
#ifdef __STL_MEMBER_TEMPLATES
  template<class _CharT, class _Traits, class _Alloc>
  void _M_copy_from_string(const basic_string<_CharT,_Traits,_Alloc>& __s,
                          size_t,
                          size_t);

  template<class _CharT, class _Traits, class _Alloc>
  void _M_copy_to_string(basic_string<_CharT,_Traits,_Alloc>&) const;
#else /* __STL_MEMBER_TEMPLATES */
  void _M_copy_from_string(const basic_string<char>&, size_t, size_t);
  void _M_copy_to_string(basic_string<char>&) const;
#endif /* __STL_MEMBER_TEMPLATES */

  size_t count() const { return this->_M_do_count(); }

  size_t size() const { return _Nb; }

  bool operator==(const bitset<_Nb>& __rhs) const {
    return this->_M_is_equal(__rhs);
  }
  bool operator!=(const bitset<_Nb>& __rhs) const {
    return !this->_M_is_equal(__rhs);
  }

  bool test(size_t __pos) const {
    if (__pos > _Nb)
      __STL_THROW(out_of_range("bitset"));

    return _Unchecked_test(__pos);
  }

  bool any() const { return this->_M_is_any(); }