summaryrefslogtreecommitdiff
path: root/o3tl/inc/o3tl/sorted_vector.hxx
blob: 48ad0bcbabb6cff0c5ad1ea270242c73fc7b4cda (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#ifndef INCLUDED_O3TL_SORTED_VECTOR_HXX
#define INCLUDED_O3TL_SORTED_VECTOR_HXX

#include <vector>
#include <functional>
#include <algorithm>

namespace o3tl
{

/** Represents a sorted vector of values.

    @tpl Value class of item to be stored in container
    @tpl Compare comparison method
*/
template <class Value, class Compare = std::less<Value> >
class sorted_vector
    : private std::vector<Value>
{
private:
    typedef typename std::vector<Value> base_t;
    typedef typename std::vector<Value>::iterator  iterator;
public:
    typedef typename std::vector<Value>::const_iterator const_iterator;
    typedef typename std::vector<Value>::size_type size_type;

    using base_t::clear;
    using base_t::erase;
    using base_t::empty;
    using base_t::size;

    // MODIFIERS

    std::pair<const_iterator,bool> insert( const Value& x )
    {
        iterator it = lower_bound_nonconst( x );
        if (it == base_t::end() || less_than(x, *it))
        {
            it = base_t::insert( it, x );
            return std::make_pair( it, true );
        }
        return std::make_pair( it, false );
    }

    size_type erase( const Value& x )
    {
        iterator it = lower_bound_nonconst( x );
        if (it != base_t::end() && !less_than(x, *it))
        {
            erase( it );
            return 1;
        }
        return 0;
    }

    void erase( size_t index )
    {
        base_t::erase( begin_nonconst() + index );
    }

    // hack: public erase with const_iterator, should not change sort order
    void erase(const_iterator const& first, const_iterator const& last)
    {
        base_t::erase(begin_nonconst() + (first - begin()),
                      begin_nonconst() + (last  - begin()));
    }

    // ACCESSORS

    // Only return a const iterator, so that the vector cannot be directly updated.
    const_iterator begin() const
    {
        return base_t::begin();
    }

    // Only return a const iterator, so that the vector cannot be directly updated.
    const_iterator end() const
    {
        return base_t::end();
    }

    const Value& front() const
    {
        return base_t::front();
    }

    const Value& back() const
    {
        return base_t::back();
    }

    const Value& operator[]( size_t index ) const
    {
        return base_t::operator[]( index );
    }

    // OPERATIONS

    const_iterator lower_bound( const Value& x ) const
    {
        return std::lower_bound( base_t::begin(), base_t::end(), x, Compare() );
    }

    /* Searches the container for an element with a value of x
     * and returns an iterator to it if found, otherwise it returns an
     * iterator to sorted_vector::end (the element past the end of the container).
     *
     * Only return a const iterator, so that the vector cannot be directly updated.
     */
    const_iterator find( const Value& x ) const
    {
        const_iterator it = lower_bound( x );
        if (it == base_t::end() || less_than(x, *it))
        {
            return base_t::end();
        }
        return it;
    }

    void insert( sorted_vector<Value,Compare> &rOther )
    {
       // optimisation for the rather common case that we are overwriting this with the contents
       // of another sorted vector
       if ( empty() )
       {
           base_t::insert( begin_nonconst(),
                   rOther.begin_nonconst(), rOther.end_nonconst() );
       }
       else
           for( const_iterator it = rOther.begin(); it != rOther.end(); ++it )
               insert( *it );
    }

    /* Clear() elements in the vector, and free them one by one. */
    void DeleteAndDestroyAll()
    {
        for( const_iterator it = begin(); it != end(); ++it )
            delete *it;
        clear();
    }

private:
    /** just makes the code easier to read */
    bool less_than(const Value& lhs, const Value& rhs) const
    {
        return Compare().operator()(lhs, rhs);
    }

    iterator lower_bound_nonconst( const Value& x )
    {
        return std::lower_bound( base_t::begin(), base_t::end(), x, Compare() );
    }

    typename base_t::iterator begin_nonconst() { return base_t::begin(); }
    typename base_t::iterator end_nonconst()   { return base_t::end(); }

};


/** Implements an ordering function over a pointer, where the comparison uses the < operator on the pointed-to types.
    Very useful for the cases where we put pointers to objects inside a sorted_vector.
*/
template <class T> struct less_ptr_to : public std::binary_function <T*,T*,bool>
{
    bool operator() ( T* const& lhs, T* const& rhs ) const
    {
        return (*lhs) < (*rhs);
    }
};


}   // namespace o3tl
#endif

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */