epoc32/include/stdapis/boost/pending/mutable_queue.hpp
author William Roberts <williamr@symbian.org>
Wed, 31 Mar 2010 12:33:34 +0100 (2010-03-31)
branchSymbian3
changeset 4 837f303aceeb
permissions -rw-r--r--
Current Symbian^3 public API header files (from PDK 3.0.h)
This is the epoc32/include tree with the "platform" subtrees removed, and
all but a selected few mbg and rsg files removed.
     1 //
     2 //=======================================================================
     3 // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
     4 // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
     5 //
     6 // Distributed under the Boost Software License, Version 1.0. (See
     7 // accompanying file LICENSE_1_0.txt or copy at
     8 // http://www.boost.org/LICENSE_1_0.txt)
     9 //=======================================================================
    10 //
    11 #ifndef BOOST_MUTABLE_QUEUE_HPP
    12 #define BOOST_MUTABLE_QUEUE_HPP
    13 
    14 #include <vector>
    15 #include <algorithm>
    16 #include <functional>
    17 #include <boost/property_map.hpp>
    18 #include <boost/pending/mutable_heap.hpp>
    19 #include <boost/pending/is_heap.hpp>
    20 #include <boost/graph/detail/array_binary_tree.hpp>
    21 #include <iterator>
    22 
    23 namespace boost {
    24 
    25   // The mutable queue whose elements are indexed
    26   // 
    27   // This adaptor provides a special kind of priority queue that has
    28   // and update operation. This allows the ordering of the items to
    29   // change. After the ordering criteria for item x changes, one must
    30   // call the Q.update(x)
    31   // 
    32   // In order to efficiently find x in the queue, a functor must be
    33   // provided to map value_type to a unique ID, which the
    34   // mutable_queue will then use to map to the location of the
    35   // item. The ID's generated must be between 0 and N, where N is the
    36   // value passed to the constructor of mutable_queue
    37 
    38   template <class IndexedType, 
    39             class RandomAccessContainer = std::vector<IndexedType>, 
    40             class Comp = std::less<typename RandomAccessContainer::value_type>,
    41             class ID = identity_property_map >
    42   class mutable_queue {
    43   public:
    44     typedef IndexedType value_type;
    45     typedef typename RandomAccessContainer::size_type size_type;
    46   protected:
    47     typedef typename RandomAccessContainer::iterator iterator;
    48 #if !defined BOOST_NO_STD_ITERATOR_TRAITS
    49     typedef  adstl::array_binary_tree_node<iterator, ID> Node;
    50 #else
    51     typedef  adstl::array_binary_tree_node<iterator, value_type, ID> Node;
    52 #endif
    53     typedef  adstl::compare_array_node<RandomAccessContainer,Comp> Compare;
    54     typedef std::vector<size_type> IndexArray;
    55   public:
    56     typedef Compare value_compare;
    57     typedef ID id_generator;
    58 
    59     mutable_queue(size_type n, const Comp& x, const ID& _id) 
    60       : index_array(n), comp(x), id(_id) {
    61       c.reserve(n); 
    62     }
    63     template <class ForwardIterator>
    64     mutable_queue(ForwardIterator first, ForwardIterator last, 
    65                   const Comp& x, const ID& _id) 
    66       : index_array(std::distance(first, last)), comp(x), id(_id)
    67     {
    68       while( first != last ) {
    69         push(*first);
    70         ++first;
    71       }
    72     }
    73 
    74     bool empty() const { return c.empty(); }
    75     
    76     void pop() {
    77       value_type tmp = c.back();
    78       c.back() = c.front();
    79       c.front() = tmp;
    80 
    81       size_type id_f = get(id, c.back());
    82       size_type id_b = get(id, tmp);
    83       size_type i = index_array[ id_b ];
    84       index_array[ id_b ] = index_array[ id_f ];
    85       index_array[ id_f ] = i;
    86 
    87       c.pop_back();
    88       Node node(c.begin(), c.end(), c.begin(), id);
    89       down_heap(node, comp, index_array);       
    90     }
    91     void push(const IndexedType& x) {
    92       c.push_back(x);
    93       /*set index-array*/
    94       index_array[ get(id, x) ] = c.size()-1;
    95       Node node(c.begin(), c.end(), c.end() - 1, id);
    96       up_heap(node, comp, index_array);
    97     }
    98 
    99     void update(const IndexedType& x) {
   100       size_type current_pos = index_array[ get(id, x) ];
   101       c[current_pos] = x;
   102 
   103       Node node(c.begin(), c.end(), c.begin()+current_pos, id);
   104       update_heap(node, comp, index_array);
   105     }
   106 
   107     value_type& front() { return c.front(); }
   108     value_type& top() { return c.front(); }
   109 
   110     const value_type& front() const { return c.front(); }
   111     const value_type& top() const { return c.front(); }
   112 
   113     size_type size() const { return c.size(); }
   114 
   115     void clear() { c.clear(); }
   116 
   117 #if 0
   118         // dwa 2003/7/11 - I don't know what compiler is supposed to
   119         // be able to compile this, but is_heap is not standard!!
   120     bool test() {
   121       return std::is_heap(c.begin(), c.end(), Comp());
   122     }
   123 #endif 
   124 
   125    protected:
   126     IndexArray index_array;
   127     Compare comp;
   128     RandomAccessContainer c;
   129     ID id;
   130   };
   131 
   132 
   133 }
   134 
   135 #endif // BOOST_MUTABLE_QUEUE_HPP