• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1[/
2 /  Copyright (c) 2002, 2003, 2005 Peter Dimov
3 /  Copyright (c) 2014 Glen Fernandes
4 /
5 /  Distributed under the Boost Software License, Version 1.0. (See
6 /  accompanying file LICENSE_1_0.txt or copy at
7 /  http://www.boost.org/LICENSE_1_0.txt)
8 /]
9
10[section:checked_delete checked_delete]
11
12[simplesect Authors]
13
14* Beman Dawes
15* Dave Abrahams
16* Vladimir Prus
17* Rainer Deyke
18* John Maddock
19
20[endsimplesect]
21
22[section Overview]
23
24The header `<boost/checked_delete.hpp>` defines two function
25templates, `checked_delete` and `checked_array_delete`, and two
26class templates, `checked_deleter` and `checked_array_deleter`.
27
28The C++ Standard allows, in 5.3.5/5, pointers to incomplete
29class types to be deleted with a delete-expression. When the
30class has a non-trivial destructor, or a class-specific
31operator delete, the behavior is undefined. Some compilers
32issue a warning when an incomplete type is deleted, but
33unfortunately, not all do, and programmers sometimes ignore or
34disable warnings.
35
36A particularly troublesome case is when a smart pointer's
37destructor, such as `boost::scoped_ptr<T>::~scoped_ptr`, is
38instantiated with an incomplete type. This can often lead to
39silent, hard to track failures.
40
41The supplied function and class templates can be used to
42prevent these problems, as they require a complete type, and
43cause a compilation error otherwise.
44
45[endsect]
46
47[section Synopsis]
48
49``
50namespace boost
51{
52    template<class T> void checked_delete(T * p);
53    template<class T> void checked_array_delete(T * p);
54    template<class T> struct checked_deleter;
55    template<class T> struct checked_array_deleter;
56}
57``
58
59[endsect]
60
61[section checked_delete]
62
63[section template<class T> void checked_delete(T * p);]
64
65* *Requires:* `T` must be a complete type. The expression
66  `delete p` must be well-formed.
67* *Effects:* `delete p;`
68
69[endsect]
70
71[endsect]
72
73[section checked_array_delete]
74
75[section template<class T> void checked_array_delete(T * p);]
76
77* *Requires:* `T` must be a complete type. The expression
78  `delete [] p` must be well-formed.
79* *Effects:* `delete [] p;`
80
81[endsect]
82
83[endsect]
84
85[section checked_deleter]
86
87``
88template<class T> struct checked_deleter
89{
90    typedef void result_type;
91    typedef T * argument_type;
92    void operator()(T * p) const;
93};
94``
95
96[section void checked_deleter<T>::operator()(T * p) const;]
97
98* *Requires:* `T` must be a complete type. The expression
99  `delete p` must be well-formed.
100* *Effects:* `delete p;`
101
102[endsect]
103
104[endsect]
105
106[section checked_array_deleter]
107
108``
109template<class T> struct checked_array_deleter
110{
111    typedef void result_type;
112    typedef T * argument_type;
113    void operator()(T * p) const;
114};
115``
116
117[section void checked_array_deleter<T>::operator()(T * p) const;]
118
119* *Requires:* `T` must be a complete type. The expression
120  `delete [] p` must be well-formed.
121* *Effects:* `delete [] p;`
122
123[endsect]
124
125[endsect]
126
127[section Acknowledgements]
128
129The function templates `checked_delete` and
130`checked_array_delete` were originally part of
131`<boost/utility.hpp>`, and the documentation
132acknowledged Beman Dawes, Dave Abrahams,
133Vladimir Prus, Rainer Deyke, John Maddock,
134and others as contributors.
135
136[endsect]
137
138[endsect]
139