1 | #ifndef BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED |
---|---|
2 | #define BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED |
3 | |
4 | // |
5 | // enable_shared_from_this.hpp |
6 | // |
7 | // Copyright 2002, 2009 Peter Dimov |
8 | // |
9 | // Distributed under the Boost Software License, Version 1.0. |
10 | // See accompanying file LICENSE_1_0.txt or copy at |
11 | // http://www.boost.org/LICENSE_1_0.txt |
12 | // |
13 | // See http://www.boost.org/libs/smart_ptr/ for documentation. |
14 | // |
15 | |
16 | #include <boost/smart_ptr/weak_ptr.hpp> |
17 | #include <boost/smart_ptr/shared_ptr.hpp> |
18 | #include <boost/smart_ptr/detail/sp_noexcept.hpp> |
19 | #include <boost/assert.hpp> |
20 | #include <boost/config.hpp> |
21 | |
22 | namespace boost |
23 | { |
24 | |
25 | template<class T> class enable_shared_from_this |
26 | { |
27 | protected: |
28 | |
29 | BOOST_CONSTEXPR enable_shared_from_this() BOOST_SP_NOEXCEPT |
30 | { |
31 | } |
32 | |
33 | BOOST_CONSTEXPR enable_shared_from_this(enable_shared_from_this const &) BOOST_SP_NOEXCEPT |
34 | { |
35 | } |
36 | |
37 | enable_shared_from_this & operator=(enable_shared_from_this const &) BOOST_SP_NOEXCEPT |
38 | { |
39 | return *this; |
40 | } |
41 | |
42 | ~enable_shared_from_this() BOOST_SP_NOEXCEPT // ~weak_ptr<T> newer throws, so this call also must not throw |
43 | { |
44 | } |
45 | |
46 | public: |
47 | |
48 | shared_ptr<T> shared_from_this() |
49 | { |
50 | shared_ptr<T> p( weak_this_ ); |
51 | BOOST_ASSERT( p.get() == this ); |
52 | return p; |
53 | } |
54 | |
55 | shared_ptr<T const> shared_from_this() const |
56 | { |
57 | shared_ptr<T const> p( weak_this_ ); |
58 | BOOST_ASSERT( p.get() == this ); |
59 | return p; |
60 | } |
61 | |
62 | weak_ptr<T> weak_from_this() BOOST_SP_NOEXCEPT |
63 | { |
64 | return weak_this_; |
65 | } |
66 | |
67 | weak_ptr<T const> weak_from_this() const BOOST_SP_NOEXCEPT |
68 | { |
69 | return weak_this_; |
70 | } |
71 | |
72 | public: // actually private, but avoids compiler template friendship issues |
73 | |
74 | // Note: invoked automatically by shared_ptr; do not call |
75 | template<class X, class Y> void _internal_accept_owner( shared_ptr<X> const * ppx, Y * py ) const BOOST_SP_NOEXCEPT |
76 | { |
77 | if( weak_this_.expired() ) |
78 | { |
79 | weak_this_ = shared_ptr<T>( *ppx, py ); |
80 | } |
81 | } |
82 | |
83 | private: |
84 | |
85 | mutable weak_ptr<T> weak_this_; |
86 | }; |
87 | |
88 | } // namespace boost |
89 | |
90 | #endif // #ifndef BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED |
91 |