source: NonGTP/Boost/boost/detail/shared_array_nmt.hpp @ 857

Revision 857, 3.3 KB checked in by igarcia, 19 years ago (diff)
Line 
1#ifndef BOOST_DETAIL_SHARED_ARRAY_NMT_HPP_INCLUDED
2#define BOOST_DETAIL_SHARED_ARRAY_NMT_HPP_INCLUDED
3
4//
5//  detail/shared_array_nmt.hpp - shared_array.hpp without member templates
6//
7//  (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
8//  Copyright (c) 2001, 2002 Peter Dimov
9//
10//  Distributed under the Boost Software License, Version 1.0. (See
11//  accompanying file LICENSE_1_0.txt or copy at
12//  http://www.boost.org/LICENSE_1_0.txt)
13//
14//  See http://www.boost.org/libs/smart_ptr/shared_array.htm for documentation.
15//
16
17#include <boost/assert.hpp>
18#include <boost/checked_delete.hpp>
19#include <boost/throw_exception.hpp>
20#include <boost/detail/atomic_count.hpp>
21
22#include <cstddef>          // for std::ptrdiff_t
23#include <algorithm>        // for std::swap
24#include <functional>       // for std::less
25#include <new>              // for std::bad_alloc
26
27namespace boost
28{
29
30template<class T> class shared_array
31{
32private:
33
34    typedef detail::atomic_count count_type;
35
36public:
37
38    typedef T element_type;
39     
40    explicit shared_array(T * p = 0): px(p)
41    {
42#ifndef BOOST_NO_EXCEPTIONS
43
44        try  // prevent leak if new throws
45        {
46            pn = new count_type(1);
47        }
48        catch(...)
49        {
50            boost::checked_array_delete(p);
51            throw;
52        }
53
54#else
55
56        pn = new count_type(1);
57
58        if(pn == 0)
59        {
60            boost::checked_array_delete(p);
61            boost::throw_exception(std::bad_alloc());
62        }
63
64#endif
65    }
66
67    ~shared_array()
68    {
69        if(--*pn == 0)
70        {
71            boost::checked_array_delete(px);
72            delete pn;
73        }
74    }
75
76    shared_array(shared_array const & r) : px(r.px)  // never throws
77    {
78        pn = r.pn;
79        ++*pn;
80    }
81
82    shared_array & operator=(shared_array const & r)
83    {
84        shared_array(r).swap(*this);
85        return *this;
86    }
87
88    void reset(T * p = 0)
89    {
90        BOOST_ASSERT(p == 0 || p != px);
91        shared_array(p).swap(*this);
92    }
93
94    T * get() const  // never throws
95    {
96        return px;
97    }
98
99    T & operator[](std::ptrdiff_t i) const  // never throws
100    {
101        BOOST_ASSERT(px != 0);
102        BOOST_ASSERT(i >= 0);
103        return px[i];
104    }
105
106    long use_count() const  // never throws
107    {
108        return *pn;
109    }
110
111    bool unique() const  // never throws
112    {
113        return *pn == 1;
114    }
115
116    void swap(shared_array<T> & other)  // never throws
117    {
118        std::swap(px, other.px);
119        std::swap(pn, other.pn);
120    }
121
122private:
123
124    T * px;            // contained pointer
125    count_type * pn;   // ptr to reference counter
126     
127};  // shared_array
128
129template<class T, class U> inline bool operator==(shared_array<T> const & a, shared_array<U> const & b)
130{
131    return a.get() == b.get();
132}
133
134template<class T, class U> inline bool operator!=(shared_array<T> const & a, shared_array<U> const & b)
135{
136    return a.get() != b.get();
137}
138
139template<class T> inline bool operator<(shared_array<T> const & a, shared_array<T> const & b)
140{
141    return std::less<T*>()(a.get(), b.get());
142}
143
144template<class T> void swap(shared_array<T> & a, shared_array<T> & b)
145{
146    a.swap(b);
147}
148
149} // namespace boost
150
151#endif  // #ifndef BOOST_DETAIL_SHARED_ARRAY_NMT_HPP_INCLUDED
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