stl_bvector.h

著名的SGI的STL lib源码.(C++范型类编成,没有合适的分类,但是放到数据结构类别中也绝对适合)

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996,1997
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */

#ifndef __SGI_STL_INTERNAL_BVECTOR_H
#define __SGI_STL_INTERNAL_BVECTOR_H

__STL_BEGIN_NAMESPACE 

static const int __WORD_BIT = int(CHAR_BIT*sizeof(unsigned int));

#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
#pragma set woff 1174
#endif

struct __bit_reference {
  unsigned int* p;
  unsigned int mask;
  __bit_reference(unsigned int* x, unsigned int y) : p(x), mask(y) {}

public:
  __bit_reference() : p(0), mask(0) {}
  operator bool() const { return !(!(*p & mask)); }
  __bit_reference& operator=(bool x) {
    if (x)      
      *p |= mask;
    else 
      *p &= ~mask;
    return *this;
  }
  __bit_reference& operator=(const __bit_reference& x) { 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() { *p ^= mask; }
};

inline void swap(__bit_reference x, __bit_reference y) {
  bool tmp = x;
  x = y;
  y = tmp;
}

struct __bit_iterator : public random_access_iterator<bool, ptrdiff_t> {
  typedef __bit_reference  reference;
  typedef __bit_reference* pointer;
  typedef __bit_iterator iterator;

  unsigned int* p;
  unsigned int offset;
  void bump_up() {
    if (offset++ == __WORD_BIT - 1) {
      offset = 0;
      ++p;
    }
  }
  void bump_down() {
    if (offset-- == 0) {
      offset = __WORD_BIT - 1;
      --p;
    }
  }

  __bit_iterator() : p(0), offset(0) {}
  __bit_iterator(unsigned int* x, unsigned int y) : p(x), offset(y) {}
  reference operator*() const { return reference(p, 1U << offset); }
  iterator& operator++() {
    bump_up();
    return *this;
  }
  iterator operator++(int) {
    iterator tmp = *this;
    bump_up();
    return tmp;
  }
  iterator& operator--() {
    bump_down();
    return *this;
  }
  iterator operator--(int) {
    iterator tmp = *this;
    bump_down();
    return tmp;
  }
  iterator& operator+=(difference_type i) {
    difference_type n = i + offset;
    p += n / __WORD_BIT;
    n = n % __WORD_BIT;
    if (n < 0) {
      offset = (unsigned int) n + __WORD_BIT;
      --p;
    } else
      offset = (unsigned int) n;
    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;
  }
  difference_type operator-(iterator x) const {
    return __WORD_BIT * (p - x.p) + offset - x.offset;
  }
  reference operator[](difference_type i) { return *(*this + i); }
  bool operator==(const iterator& x) const {
    return p == x.p && offset == x.offset;
  }
  bool operator!=(const iterator& x) const {
    return p != x.p || offset != x.offset;
  }
  bool operator<(iterator x) const {
    return p < x.p || (p == x.p && offset < x.offset);
  }
};

struct __bit_const_iterator
  : public random_access_iterator<bool, ptrdiff_t>
{
  typedef bool                 reference;
  typedef bool                 const_reference;
  typedef const bool*          pointer;
  typedef __bit_const_iterator const_iterator;

  unsigned int* p;
  unsigned int offset;
  void bump_up() {
    if (offset++ == __WORD_BIT - 1) {
      offset = 0;
      ++p;
    }
  }
  void bump_down() {
    if (offset-- == 0) {
      offset = __WORD_BIT - 1;
      --p;
    }
  }

  __bit_const_iterator() : p(0), offset(0) {}
  __bit_const_iterator(unsigned int* x, unsigned int y) : p(x), offset(y) {}
  __bit_const_iterator(const __bit_iterator& x) : p(x.p), offset(x.offset) {}
  const_reference operator*() const {
    return __bit_reference(p, 1U << offset);
  }
  const_iterator& operator++() {
    bump_up();
    return *this;
  }
  const_iterator operator++(int) {
    const_iterator tmp = *this;
    bump_up();
    return tmp;
  }
  const_iterator& operator--() {
    bump_down();
    return *this;
  }
  const_iterator operator--(int) {
    const_iterator tmp = *this;
    bump_down();
    return tmp;
  }
  const_iterator& operator+=(difference_type i) {
    difference_type n = i + offset;
    p += n / __WORD_BIT;
    n = n % __WORD_BIT;
    if (n < 0) {
      offset = (unsigned int) n + __WORD_BIT;
      --p;
    } else
      offset = (unsigned int) n;
    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;
  }
  difference_type operator-(const_iterator x) const {
    return __WORD_BIT * (p - x.p) + offset - x.offset;
  }
  const_reference operator[](difference_type i) { 
    return *(*this + i); 
  }
  bool operator==(const const_iterator& x) const {
    return p == x.p && offset == x.offset;
  }
  bool operator!=(const const_iterator& x) const {
    return p != x.p || offset != x.offset;
  }
  bool operator<(const_iterator x) const {
    return p < x.p || (p == x.p && offset < x.offset);
  }
};

// The next few lines are confusing.  What we're doing is declaring a
//  partial specialization of vector<T, Alloc> if we have the necessary
//  compiler support.  Otherwise, we define a class bit_vector which uses
//  the default allocator.  In either case, we typedef "data_allocator" 
//  appropriately.

#if defined(__STL_CLASS_PARTIAL_SPECIALIZATION) && !defined(__STL_NEED_BOOL)
#define __SGI_STL_VECBOOL_TEMPLATE
#define __BVECTOR vector
#else
#undef __SGI_STL_VECBOOL_TEMPLATE
#define __BVECTOR bit_vector
#endif

#      ifdef __SGI_STL_VECBOOL_TEMPLATE
       __STL_END_NAMESPACE
#      include <stl_vector.h>
       __STL_BEGIN_NAMESPACE
template<class Alloc> class vector<bool, Alloc>
#      else /* __SGI_STL_VECBOOL_TEMPLATE */
class bit_vector
#      endif /* __SGI_STL_VECBOOL_TEMPLATE */
{
#      ifdef __SGI_STL_VECBOOL_TEMPLATE
  typedef simple_alloc<unsigned int, Alloc> data_allocator;
#      else /* __SGI_STL_VECBOOL_TEMPLATE */
  typedef simple_alloc<unsigned int, alloc> data_allocator;  
#      endif /* __SGI_STL_VECBOOL_TEMPLATE */
public:
  typedef bool value_type;
  typedef size_t size_type;
  typedef ptrdiff_t difference_type; 
  typedef __bit_reference reference;
  typedef bool const_reference;
  typedef __bit_reference* pointer;
  typedef const bool* const_pointer;

  typedef __bit_iterator                iterator;
  typedef __bit_const_iterator          const_iterator;

#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
  typedef reverse_iterator<const_iterator> const_reverse_iterator;
  typedef reverse_iterator<iterator> reverse_iterator;
#else /* __STL_CLASS_PARTIAL_SPECIALIZATION */
  typedef reverse_iterator<const_iterator, value_type, const_reference, 
                           difference_type> const_reverse_iterator;
  typedef reverse_iterator<iterator, value_type, reference, difference_type>
          reverse_iterator;
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

protected:
  iterator start;
  iterator finish;
  unsigned int* end_of_storage;
  unsigned int* bit_alloc(size_type n) {
    return data_allocator::allocate((n + __WORD_BIT - 1)/__WORD_BIT);
  }
  void deallocate() {
    if (start.p)
      data_allocator::deallocate(start.p, end_of_storage - start.p);
  }
  void initialize(size_type n) {
    unsigned int* q = bit_alloc(n);
    end_of_storage = q + (n + __WORD_BIT - 1)/__WORD_BIT;
    start = iterator(q, 0);
    finish = start + difference_type(n);
  }
  void insert_aux(iterator position, bool x) {
    if (finish.p != end_of_storage) {
      copy_backward(position, finish, finish + 1);
      *position = x;