stl_deque.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) 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_DEQUE_H
#define __SGI_STL_INTERNAL_DEQUE_H

/* Class invariants:
 *  For any nonsingular iterator i:
 *    i.node is the address of an element in the map array.  The
 *      contents of i.node is a pointer to the beginning of a node.
 *    i.first == *(i.node) 
 *    i.last  == i.first + node_size
 *    i.cur is a pointer in the range [i.first, i.last).  NOTE:
 *      the implication of this is that i.cur is always a dereferenceable
 *      pointer, even if i is a past-the-end iterator.
 *  Start and Finish are always nonsingular iterators.  NOTE: this means
 *    that an empty deque must have one node, and that a deque
 *    with N elements, where N is the buffer size, must have two nodes.
 *  For every node other than start.node and finish.node, every element
 *    in the node is an initialized object.  If start.node == finish.node,
 *    then [start.cur, finish.cur) are initialized objects, and
 *    the elements outside that range are uninitialized storage.  Otherwise,
 *    [start.cur, start.last) and [finish.first, finish.cur) are initialized
 *    objects, and [start.first, start.cur) and [finish.cur, finish.last)
 *    are uninitialized storage.
 *  [map, map + map_size) is a valid, non-empty range.  
 *  [start.node, finish.node] is a valid range contained within 
 *    [map, map + map_size).  
 *  A pointer in the range [map, map + map_size) points to an allocated
 *    node if and only if the pointer is in the range [start.node, finish.node].
 */


/*
 * In previous versions of deque, node_size was fixed by the 
 * implementation.  In this version, however, users can select
 * the node size.  Deque has three template parameters; the third,
 * a number of type size_t, is the number of elements per node.
 * If the third template parameter is 0 (which is the default), 
 * then deque will use a default node size.
 *
 * The only reason for using an alternate node size is if your application
 * requires a different performance tradeoff than the default.  If,
 * for example, your program contains many deques each of which contains
 * only a few elements, then you might want to save memory (possibly
 * by sacrificing some speed) by using smaller nodes.
 *
 * Unfortunately, some compilers have trouble with non-type template 
 * parameters; stl_config.h defines __STL_NON_TYPE_TMPL_PARAM_BUG if
 * that is the case.  If your compiler is one of them, then you will
 * not be able to use alternate node sizes; you will have to use the
 * default value.
 */

__STL_BEGIN_NAMESPACE 

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

// Note: this function is simply a kludge to work around several compilers'
//  bugs in handling constant expressions.
inline size_t __deque_buf_size(size_t n, size_t sz)
{
  return n != 0 ? n : (sz < 512 ? size_t(512 / sz) : size_t(1));
}

#ifndef __STL_NON_TYPE_TMPL_PARAM_BUG
template <class T, class Ref, class Ptr, size_t BufSiz>
struct __deque_iterator {
  typedef __deque_iterator<T, T&, T*, BufSiz>             iterator;
  typedef __deque_iterator<T, const T&, const T*, BufSiz> const_iterator;
  static size_t buffer_size() {return __deque_buf_size(BufSiz, sizeof(T)); }
#else /* __STL_NON_TYPE_TMPL_PARAM_BUG */
template <class T, class Ref, class Ptr>
struct __deque_iterator {
  typedef __deque_iterator<T, T&, T*>             iterator;
  typedef __deque_iterator<T, const T&, const T*> const_iterator;
  static size_t buffer_size() {return __deque_buf_size(0, sizeof(T)); }
#endif

  typedef random_access_iterator_tag iterator_category;
  typedef T value_type;
  typedef Ptr pointer;
  typedef Ref reference;
  typedef size_t size_type;
  typedef ptrdiff_t difference_type;
  typedef T** map_pointer;

  typedef __deque_iterator self;

  T* cur;
  T* first;
  T* last;
  map_pointer node;

  __deque_iterator(T* x, map_pointer y) 
    : cur(x), first(*y), last(*y + buffer_size()), node(y) {}
  __deque_iterator() : cur(0), first(0), last(0), node(0) {}
  __deque_iterator(const iterator& x)
    : cur(x.cur), first(x.first), last(x.last), node(x.node) {}

  reference operator*() const { return *cur; }
#ifndef __SGI_STL_NO_ARROW_OPERATOR
  pointer operator->() const { return &(operator*()); }
#endif /* __SGI_STL_NO_ARROW_OPERATOR */

  difference_type operator-(const self& x) const {
    return difference_type(buffer_size()) * (node - x.node - 1) +
      (cur - first) + (x.last - x.cur);
  }

  self& operator++() {
    ++cur;
    if (cur == last) {
      set_node(node + 1);
      cur = first;
    }
    return *this; 
  }
  self operator++(int)  {
    self tmp = *this;
    ++*this;
    return tmp;
  }

  self& operator--() {
    if (cur == first) {
      set_node(node - 1);
      cur = last;
    }
    --cur;
    return *this;
  }
  self operator--(int) {
    self tmp = *this;
    --*this;
    return tmp;
  }

  self& operator+=(difference_type n) {
    difference_type offset = n + (cur - first);
    if (offset >= 0 && offset < difference_type(buffer_size()))
      cur += n;
    else {
      difference_type node_offset =
        offset > 0 ? offset / difference_type(buffer_size())
                   : -difference_type((-offset - 1) / buffer_size()) - 1;
      set_node(node + node_offset);
      cur = first + (offset - node_offset * difference_type(buffer_size()));
    }
    return *this;
  }

  self operator+(difference_type n) const {
    self tmp = *this;
    return tmp += n;
  }

  self& operator-=(difference_type n) { return *this += -n; }
 
  self operator-(difference_type n) const {
    self tmp = *this;
    return tmp -= n;
  }

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

  bool operator==(const self& x) const { return cur == x.cur; }
  bool operator!=(const self& x) const { return !(*this == x); }
  bool operator<(const self& x) const {
    return (node == x.node) ? (cur < x.cur) : (node < x.node);
  }

  void set_node(map_pointer new_node) {
    node = new_node;
    first = *new_node;
    last = first + difference_type(buffer_size());
  }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

#ifndef __STL_NON_TYPE_TMPL_PARAM_BUG

template <class T, class Ref, class Ptr, size_t BufSiz>
inline random_access_iterator_tag
iterator_category(const __deque_iterator<T, Ref, Ptr, BufSiz>&) {
  return random_access_iterator_tag();
}

template <class T, class Ref, class Ptr, size_t BufSiz>
inline T* value_type(const __deque_iterator<T, Ref, Ptr, BufSiz>&) {
  return 0;
}

template <class T, class Ref, class Ptr, size_t BufSiz>
inline ptrdiff_t* distance_type(const __deque_iterator<T, Ref, Ptr, BufSiz>&) {
  return 0;
}

#else /* __STL_NON_TYPE_TMPL_PARAM_BUG */

template <class T, class Ref, class Ptr>
inline random_access_iterator_tag
iterator_category(const __deque_iterator<T, Ref, Ptr>&) {
  return random_access_iterator_tag();
}

template <class T, class Ref, class Ptr>
inline T* value_type(const __deque_iterator<T, Ref, Ptr>&) { return 0; }

template <class T, class Ref, class Ptr>
inline ptrdiff_t* distance_type(const __deque_iterator<T, Ref, Ptr>&) {
  return 0;
}

#endif /* __STL_NON_TYPE_TMPL_PARAM_BUG */

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

// See __deque_buf_size().  The only reason that the default value is 0
//  is as a workaround for bugs in the way that some compilers handle
//  constant expressions.
template <class T, class Alloc = alloc, size_t BufSiz = 0> 
class deque {
public:                         // Basic types
  typedef T value_type;
  typedef value_type* pointer;
  typedef const value_type* const_pointer;
  typedef value_type& reference;
  typedef const value_type& const_reference;
  typedef size_t size_type;
  typedef ptrdiff_t difference_type;

public:                         // Iterators
#ifndef __STL_NON_TYPE_TMPL_PARAM_BUG
  typedef __deque_iterator<T, T&, T*, BufSiz>              iterator;
  typedef __deque_iterator<T, const T&, const T&, BufSiz>  const_iterator;
#else /* __STL_NON_TYPE_TMPL_PARAM_BUG */
  typedef __deque_iterator<T, T&, T*>                      iterator;
  typedef __deque_iterator<T, const T&, const T*>          const_iterator;
#endif /* __STL_NON_TYPE_TMPL_PARAM_BUG */

#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:                      // Internal typedefs
  typedef pointer* map_pointer;
  typedef simple_alloc<value_type, Alloc> data_allocator;
  typedef simple_alloc<pointer, Alloc> map_allocator;

  static size_type buffer_size() {
    return __deque_buf_size(BufSiz, sizeof(value_type));
  }
  static size_type initial_map_size() { return 8; }

protected:                      // Data members
  iterator start;
  iterator finish;

  map_pointer map;
  size_type map_size;

public:                         // Basic accessors
  iterator begin() { return start; }
  iterator end() { return finish; }
  const_iterator begin() const { return start; }
  const_iterator end() const { return finish; }

  reverse_iterator rbegin() { return reverse_iterator(finish); }
  reverse_iterator rend() { return reverse_iterator(start); }
  const_reverse_iterator rbegin() const {
    return const_reverse_iterator(finish);
  }
  const_reverse_iterator rend() const {
    return const_reverse_iterator(start);
  }

  reference operator[](size_type n) { return start[difference_type(n)]; }
  const_reference operator[](size_type n) const {
    return start[difference_type(n)];
  }

  reference front() { return *start; }
  reference back() {
    iterator tmp = finish;
    --tmp;
    return *tmp;
  }
  const_reference front() const { return *start; }
  const_reference back() const {
    const_iterator tmp = finish;
    --tmp;
    return *tmp;
  }

  size_type size() const { return finish - start;; }
  size_type max_size() const { return size_type(-1); }
  bool empty() const { return finish == start; }

public:                         // Constructor, destructor.
  deque()
    : start(), finish(), map(0), map_size(0)
  {
    create_map_and_nodes(0);
  }

  deque(const deque& x)
    : start(), finish(), map(0), map_size(0)
  {
    create_map_and_nodes(x.size());
    __STL_TRY {
      uninitialized_copy(x.begin(), x.end(), start);
    }
    __STL_UNWIND(destroy_map_and_nodes());
  }

  deque(size_type n, const value_type& value)
    : start(), finish(), map(0), map_size(0)
  {
    fill_initialize(n, value);
  }

  deque(int n, const value_type& value)
    : start(), finish(), map(0), map_size(0)
  {
    fill_initialize(n, value);
  }
 
  deque(long n, const value_type& value)
    : start(), finish(), map(0), map_size(0)
  {
    fill_initialize(n, value);
  }

  explicit deque(size_type n)
    : start(), finish(), map(0), map_size(0)
  {
    fill_initialize(n, value_type());
  }

#ifdef __STL_MEMBER_TEMPLATES

  template <class InputIterator>
  deque(InputIterator first, InputIterator last)
    : start(), finish(), map(0), map_size(0)
  {
    range_initialize(first, last, iterator_category(first));
  }

#else /* __STL_MEMBER_TEMPLATES */

  deque(const value_type* first, const value_type* last)
    : start(), finish(), map(0), map_size(0)
  {
    create_map_and_nodes(last - first);
    __STL_TRY {
      uninitialized_copy(first, last, start);
    }
    __STL_UNWIND(destroy_map_and_nodes());
  }

  deque(const_iterator first, const_iterator last)
    : start(), finish(), map(0), map_size(0)
  {
    create_map_and_nodes(last - first);
    __STL_TRY {
      uninitialized_copy(first, last, start);
    }
    __STL_UNWIND(destroy_map_and_nodes());
  }

#endif /* __STL_MEMBER_TEMPLATES */

  ~deque() {
    destroy(start, finish);
    destroy_map_and_nodes();
  }

  deque& operator= (const deque& x) {
    const size_type len = size();
    if (&x != this) {
      if (len >= x.size())
        erase(copy(x.begin(), x.end(), start), finish);
      else {
        const_iterator mid = x.begin() + difference_type(len);
        copy(x.begin(), mid, start);
        insert(finish, mid, x.end());
      }
    }
    return *this;
  }        

  void swap(deque& x) {
    __STD::swap(start, x.start);
    __STD::swap(finish, x.finish);
    __STD::swap(map, x.map);
    __STD::swap(map_size, x.map_size);
  }

public:                         // push_* and pop_*
  
  void push_back(const value_type& t) {
    if (finish.cur != finish.last - 1) {
      construct(finish.cur, t);
      ++finish.cur;
    }
    else
      push_back_aux(t);
  }