stl_bvector.h File Reference

#include <bits/stl_vector.h>

Go to the source code of this file.

Functions
namespace std	_GLIBCXX_VISIBILITY (default)

Detailed Description

This is an internal header file, included by other library headers. Do not attempt to use it directly. {vector}

Function Documentation

namespace std _GLIBCXX_VISIBILITY

(

default

)

A specialization of vector for booleans which offers fixed time access to individual elements in any order.

Template Parameters

_Alloc

Allocator type.

Note that vector<bool> does not actually meet the requirements for being a container. This is because the reference and pointer types are not really references and pointers to bool. See DR96 for details.

See Also

vector for function documentation.

In some terminology a vector can be described as a dynamic C-style array, it offers fast and efficient access to individual elements in any order and saves the user from worrying about memory and size allocation. Subscripting ( [] ) access is also provided as with C-style arrays.

{
_GLIBCXX_BEGIN_NAMESPACE_CONTAINER

  typedef unsigned long _Bit_type;
  enum { _S_word_bit = int(__CHAR_BIT__ * sizeof(_Bit_type)) };

  struct _Bit_reference
  {
    _Bit_type * _M_p;
    _Bit_type _M_mask;

    _Bit_reference(_Bit_type * __x, _Bit_type __y)
    : _M_p(__x), _M_mask(__y) { }

    _Bit_reference() _GLIBCXX_NOEXCEPT : _M_p(0), _M_mask(0) { }

    operator bool() const _GLIBCXX_NOEXCEPT
    { return !!(*_M_p & _M_mask); }

    _Bit_reference&
    operator=(bool __x) _GLIBCXX_NOEXCEPT
    {
      if (__x)
    *_M_p |= _M_mask;
      else
    *_M_p &= ~_M_mask;
      return *this;
    }

    _Bit_reference&
    operator=(const _Bit_reference& __x) _GLIBCXX_NOEXCEPT
    { return *this = bool(__x); }

    bool
    operator==(const _Bit_reference& __x) const
    { return bool(*this) == bool(__x); }

    bool
    operator<(const _Bit_reference& __x) const
    { return !bool(*this) && bool(__x); }

    void
    flip() _GLIBCXX_NOEXCEPT
    { *_M_p ^= _M_mask; }
  };

#if __cplusplus >= 201103L
  inline void
  swap(_Bit_reference __x, _Bit_reference __y) noexcept
  {
    bool __tmp = __x;
    __x = __y;
    __y = __tmp;
  }

  inline void
  swap(_Bit_reference __x, bool& __y) noexcept
  {
    bool __tmp = __x;
    __x = __y;
    __y = __tmp;
  }

  inline void
  swap(bool& __x, _Bit_reference __y) noexcept
  {
    bool __tmp = __x;
    __x = __y;
    __y = __tmp;
  }
#endif

  struct _Bit_iterator_base
  : public std::iterator<std::random_access_iterator_tag, bool>
  {
    _Bit_type * _M_p;
    unsigned int _M_offset;

    _Bit_iterator_base(_Bit_type * __x, unsigned int __y)
    : _M_p(__x), _M_offset(__y) { }

    void
    _M_bump_up()
    {
      if (_M_offset++ == int(_S_word_bit) - 1)
    {
      _M_offset = 0;
      ++_M_p;
    }
    }

    void
    _M_bump_down()
    {
      if (_M_offset-- == 0)
    {
      _M_offset = int(_S_word_bit) - 1;
      --_M_p;
    }
    }

    void
    _M_incr(ptrdiff_t __i)
    {
      difference_type __n = __i + _M_offset;
      _M_p += __n / int(_S_word_bit);
      __n = __n % int(_S_word_bit);
      if (__n < 0)
    {
      __n += int(_S_word_bit);
      --_M_p;
    }
      _M_offset = static_cast<unsigned int>(__n);
    }

    bool
    operator==(const _Bit_iterator_base& __i) const
    { return _M_p == __i._M_p && _M_offset == __i._M_offset; }

    bool
    operator<(const _Bit_iterator_base& __i) const
    {
      return _M_p < __i._M_p
         || (_M_p == __i._M_p && _M_offset < __i._M_offset);
    }

    bool
    operator!=(const _Bit_iterator_base& __i) const
    { return !(*this == __i); }

    bool
    operator>(const _Bit_iterator_base& __i) const
    { return __i < *this; }

    bool
    operator<=(const _Bit_iterator_base& __i) const
    { return !(__i < *this); }

    bool
    operator>=(const _Bit_iterator_base& __i) const
    { return !(*this < __i); }
  };

  inline ptrdiff_t
  operator-(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
  {
    return (int(_S_word_bit) * (__x._M_p - __y._M_p)
        + __x._M_offset - __y._M_offset);
  }

  struct _Bit_iterator : public _Bit_iterator_base
  {
    typedef _Bit_reference  reference;
    typedef _Bit_reference* pointer;
    typedef _Bit_iterator   iterator;

    _Bit_iterator() : _Bit_iterator_base(0, 0) { }

    _Bit_iterator(_Bit_type * __x, unsigned int __y)
    : _Bit_iterator_base(__x, __y) { }

    reference
    operator*() const
    { return reference(_M_p, 1UL << _M_offset); }

    iterator&
    operator++()
    {
      _M_bump_up();
      return *this;
    }

    iterator
    operator++(int)
    {
      iterator __tmp = *this;
      _M_bump_up();
      return __tmp;
    }

    iterator&
    operator--()
    {
      _M_bump_down();
      return *this;
    }

    iterator
    operator--(int)
    {
      iterator __tmp = *this;
      _M_bump_down();
      return __tmp;
    }

    iterator&
    operator+=(difference_type __i)
    {
      _M_incr(__i);
      return *this;
    }

    iterator&
    operator-=(difference_type __i)
    {
      *this += -__i;
      return *this;
    }

    iterator
    operator+(difference_type __i) const
    {
      iterator __tmp = *this;
      return __tmp += __i;
    }

    iterator
    operator-(difference_type __i) const
    {
      iterator __tmp = *this;
      return __tmp -= __i;
    }

    reference
    operator[](difference_type __i) const
    { return *(*this + __i); }
  };

  inline _Bit_iterator
  operator+(ptrdiff_t __n, const _Bit_iterator& __x)
  { return __x + __n; }

  struct _Bit_const_iterator : public _Bit_iterator_base
  {
    typedef bool                 reference;
    typedef bool                 const_reference;
    typedef const bool*          pointer;
    typedef _Bit_const_iterator  const_iterator;

    _Bit_const_iterator() : _Bit_iterator_base(0, 0) { }

    _Bit_const_iterator(_Bit_type * __x, unsigned int __y)
    : _Bit_iterator_base(__x, __y) { }

    _Bit_const_iterator(const _Bit_iterator& __x)
    : _Bit_iterator_base(__x._M_p, __x._M_offset) { }

    const_reference
    operator*() const
    { return _Bit_reference(_M_p, 1UL << _M_offset); }

    const_iterator&
    operator++()
    {
      _M_bump_up();
      return *this;
    }

    const_iterator
    operator++(int)
    {
      const_iterator __tmp = *this;
      _M_bump_up();
      return __tmp;
    }

    const_iterator&
    operator--()
    {
      _M_bump_down();
      return *this;
    }

    const_iterator
    operator--(int)
    {
      const_iterator __tmp = *this;
      _M_bump_down();
      return __tmp;
    }

    const_iterator&
    operator+=(difference_type __i)
    {
      _M_incr(__i);
      return *this;
    }

    const_iterator&
    operator-=(difference_type __i)
    {
      *this += -__i;
      return *this;
    }

    const_iterator 
    operator+(difference_type __i) const
    {
      const_iterator __tmp = *this;
      return __tmp += __i;
    }

    const_iterator
    operator-(difference_type __i) const
    {
      const_iterator __tmp = *this;
      return __tmp -= __i;
    }

    const_reference
    operator[](difference_type __i) const
    { return *(*this + __i); }
  };

  inline _Bit_const_iterator
  operator+(ptrdiff_t __n, const _Bit_const_iterator& __x)
  { return __x + __n; }

  inline void
  __fill_bvector(_Bit_iterator __first, _Bit_iterator __last, bool __x)
  {
    for (; __first != __last; ++__first)
      *__first = __x;
  }

  inline void
  fill(_Bit_iterator __first, _Bit_iterator __last, const bool& __x)
  {
    if (__first._M_p != __last._M_p)
      {
    std::fill(__first._M_p + 1, __last._M_p, __x ? ~0 : 0);
    __fill_bvector(__first, _Bit_iterator(__first._M_p + 1, 0), __x);
    __fill_bvector(_Bit_iterator(__last._M_p, 0), __last, __x);
      }
    else
      __fill_bvector(__first, __last, __x);
  }

  template<typename _Alloc>
    struct _Bvector_base
    {
      typedef typename _Alloc::template rebind<_Bit_type>::other
        _Bit_alloc_type;
      
      struct _Bvector_impl
      : public _Bit_alloc_type
      {
    _Bit_iterator   _M_start;
    _Bit_iterator   _M_finish;
    _Bit_type*  _M_end_of_storage;

    _Bvector_impl()
    : _Bit_alloc_type(), _M_start(), _M_finish(), _M_end_of_storage(0)
    { }
 
    _Bvector_impl(const _Bit_alloc_type& __a)
    : _Bit_alloc_type(__a), _M_start(), _M_finish(), _M_end_of_storage(0)
    { }

#if __cplusplus >= 201103L
    _Bvector_impl(_Bit_alloc_type&& __a)
    : _Bit_alloc_type(std::move(__a)), _M_start(), _M_finish(),
      _M_end_of_storage(0)
    { }
#endif
      };

    public:
      typedef _Alloc allocator_type;

      _Bit_alloc_type&
      _M_get_Bit_allocator() _GLIBCXX_NOEXCEPT
      { return *static_cast<_Bit_alloc_type*>(&this->_M_impl); }

      const _Bit_alloc_type&
      _M_get_Bit_allocator() const _GLIBCXX_NOEXCEPT
      { return *static_cast<const _Bit_alloc_type*>(&this->_M_impl); }

      allocator_type
      get_allocator() const _GLIBCXX_NOEXCEPT
      { return allocator_type(_M_get_Bit_allocator()); }

      _Bvector_base()
      : _M_impl() { }
      
      _Bvector_base(const allocator_type& __a)
      : _M_impl(__a) { }

#if __cplusplus >= 201103L
      _Bvector_base(_Bvector_base&& __x) noexcept
      : _M_impl(std::move(__x._M_get_Bit_allocator()))
      {
    this->_M_impl._M_start = __x._M_impl._M_start;
    this->_M_impl._M_finish = __x._M_impl._M_finish;
    this->_M_impl._M_end_of_storage = __x._M_impl._M_end_of_storage;
    __x._M_impl._M_start = _Bit_iterator();
    __x._M_impl._M_finish = _Bit_iterator();
    __x._M_impl._M_end_of_storage = 0;
      }
#endif

      ~_Bvector_base()
      { this->_M_deallocate(); }

    protected:
      _Bvector_impl _M_impl;

      _Bit_type*
      _M_allocate(size_t __n)
      { return _M_impl.allocate(_S_nword(__n)); }

      void
      _M_deallocate()
      {
    if (_M_impl._M_start._M_p)
      _M_impl.deallocate(_M_impl._M_start._M_p,
                 _M_impl._M_end_of_storage - _M_impl._M_start._M_p);
      }

      static size_t
      _S_nword(size_t __n)
      { return (__n + int(_S_word_bit) - 1) / int(_S_word_bit); }
    };

_GLIBCXX_END_NAMESPACE_CONTAINER
} // namespace std