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7c673cae | 1 | /*============================================================================= |
b32b8144 | 2 | Copyright (c) 2010.2017 Daniel James |
7c673cae FG |
3 | |
4 | Use, modification and distribution is subject to the Boost Software | |
5 | License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
6 | http://www.boost.org/LICENSE_1_0.txt) | |
7 | =============================================================================*/ | |
8 | ||
7c673cae FG |
9 | #if !defined(BOOST_SPIRIT_QUICKBOOK_CLEANUP_HPP) |
10 | #define BOOST_SPIRIT_QUICKBOOK_CLEANUP_HPP | |
11 | ||
7c673cae FG |
12 | namespace quickbook |
13 | { | |
b32b8144 FG |
14 | // This header defines a class which will store pointers and delete what |
15 | // they're pointing to on destruction. Add an object, and you can use | |
16 | // pointers and references to it during the cleanup object's lifespan. | |
17 | // | |
18 | // Example use: | |
19 | // | |
20 | // struct wonder_struct { | |
21 | // quickbook::cleanup cleanup; | |
22 | // }; | |
23 | // | |
24 | // wonder_struct w; | |
25 | // thing& t = w.cleanup.add(new thing()); | |
26 | // | |
27 | // Can now use 't' until the wonder_struct is destroyed. | |
28 | // | |
29 | // Anything added to cleanup is destroyed in reverse order, so it | |
30 | // should be okay for an object to depend on something that was previously | |
31 | // added. | |
32 | ||
33 | namespace detail { struct cleanup_node; } | |
34 | struct cleanup | |
35 | { | |
36 | cleanup() : first_(0) {} | |
37 | ~cleanup(); | |
38 | template <typename T> T& add(T*); | |
39 | ||
40 | private: | |
41 | detail::cleanup_node* first_; | |
42 | ||
43 | cleanup& operator=(cleanup const&); | |
44 | cleanup(cleanup const&); | |
45 | }; | |
46 | ||
7c673cae FG |
47 | namespace detail |
48 | { | |
49 | template <typename T> | |
50 | void delete_impl(void* ptr) { | |
51 | delete static_cast<T*>(ptr); | |
52 | } | |
53 | ||
b32b8144 | 54 | struct cleanup_node |
7c673cae FG |
55 | { |
56 | void* ptr_; | |
57 | void (*del_)(void*); | |
b32b8144 | 58 | cleanup_node* next_; |
7c673cae | 59 | |
b32b8144 FG |
60 | cleanup_node() : ptr_(0), del_(0), next_(0) {} |
61 | cleanup_node(void* ptr, void (*del)(void* x)) | |
62 | : ptr_(ptr), del_(del), next_(0) {} | |
63 | ~cleanup_node() { | |
7c673cae FG |
64 | if(ptr_) del_(ptr_); |
65 | } | |
66 | ||
b32b8144 FG |
67 | void move_assign(cleanup_node& n) { |
68 | ptr_ = n.ptr_; | |
69 | del_ = n.del_; | |
70 | n.ptr_ = 0; | |
71 | n.del_ = 0; | |
7c673cae FG |
72 | } |
73 | private: | |
b32b8144 FG |
74 | cleanup_node(cleanup_node const&); |
75 | cleanup_node& operator=(cleanup_node const&); | |
7c673cae FG |
76 | }; |
77 | } | |
78 | ||
b32b8144 FG |
79 | template <typename T> |
80 | T& cleanup::add(T* ptr) | |
7c673cae | 81 | { |
b32b8144 FG |
82 | detail::cleanup_node n(ptr, &detail::delete_impl<T>); |
83 | detail::cleanup_node* n2 = new detail::cleanup_node(); | |
84 | n2->next_ = first_; | |
85 | first_ = n2; | |
86 | n2->move_assign(n); | |
87 | return *ptr; | |
88 | } | |
7c673cae | 89 | |
b32b8144 FG |
90 | inline cleanup::~cleanup() { |
91 | while(first_) { | |
92 | detail::cleanup_node* to_delete = first_; | |
93 | first_ = first_->next_; | |
94 | delete to_delete; | |
7c673cae | 95 | } |
b32b8144 | 96 | } |
7c673cae FG |
97 | } |
98 | ||
99 | #endif |