1 // Copyright (c) 2003 Daniel Wallin and Arvid Norberg
2 
3 // Permission is hereby granted, free of charge, to any person obtaining a
4 // copy of this software and associated documentation files (the "Software"),
5 // to deal in the Software without restriction, including without limitation
6 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
7 // and/or sell copies of the Software, and to permit persons to whom the
8 // Software is furnished to do so, subject to the following conditions:
9 
10 // The above copyright notice and this permission notice shall be included
11 // in all copies or substantial portions of the Software.
12 
13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
14 // ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
15 // TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
16 // PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
17 // SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
18 // ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
19 // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
21 // OR OTHER DEALINGS IN THE SOFTWARE.
22 
23 
24 #ifndef LUABIND_DEPENDENCY_POLICY_HPP_INCLUDED
25 #define LUABIND_DEPENDENCY_POLICY_HPP_INCLUDED
26 
27 #include <luabind/config.hpp>
28 #include <luabind/detail/policy.hpp>
29 
30 namespace luabind { namespace detail
31 {
32 	// makes A dependent on B, meaning B will outlive A.
33 	// internally A stores a reference to B
34 	template<int A, int B>
35 	struct dependency_policy
36 	{
postcallluabind::detail::dependency_policy37 		static void postcall(lua_State* L, const index_map& indices)
38 		{
39 			int nurse_index = indices[A];
40 			int patient = indices[B];
41 
42 			object_rep* nurse = static_cast<object_rep*>(lua_touserdata(L, nurse_index));
43 
44 			// If the nurse isn't an object_rep, just make this a nop.
45 			if (nurse == 0)
46 				return;
47 
48 			nurse->add_dependency(L, patient);
49 		}
50 	};
51 
52 }}
53 
54 #if defined (BOOST_MSVC) && (BOOST_MSVC <= 1200)
55 
56 namespace luabind
57 {
58 	// most absurd workaround of all time?
59 	namespace detail
60 	{
61 		template<int N>
62 		struct size_char_array
63 		{
64 			char storage[N + 2];
65 		};
66 
67 		template<int N>
68 		size_char_array<N> deduce_size(LUABIND_PLACEHOLDER_ARG(N));
69 
70 		template<class T>
71 		struct get_index_workaround
72 		{
73 			static T t;
74 			BOOST_STATIC_CONSTANT(int, value = sizeof(deduce_size(t)) - 2);
75 		};
76 	}
77 
78 	template<class A, class B>
79 	detail::policy_cons<detail::dependency_policy<detail::get_index_workaround<A>::value
dependency(A,B)80 		, detail::get_index_workaround<B>::value>, detail::null_type> dependency(A,B)
81 	{
82 		return detail::policy_cons<detail::dependency_policy<
83 			detail::get_index_workaround<A>::value, detail::get_index_workaround<B>::value>
84 			, detail::null_type>();
85 	}
86 
87 	template<class A>
88 	detail::policy_cons<detail::dependency_policy<0
89 		, detail::get_index_workaround<A>::value>, detail::null_type>
return_internal_reference(A)90 	return_internal_reference(A)
91 	{
92 		return detail::policy_cons<detail::dependency_policy<0
93 			, detail::get_index_workaround<A>::value>, detail::null_type>();
94 	}
95 }
96 
97 #else
98 
99 namespace luabind
100 {
101 	template<int A, int B>
102 	detail::policy_cons<detail::dependency_policy<A, B>, detail::null_type>
dependency(LUABIND_PLACEHOLDER_ARG (A),LUABIND_PLACEHOLDER_ARG (B))103 	dependency(LUABIND_PLACEHOLDER_ARG(A), LUABIND_PLACEHOLDER_ARG(B))
104 	{
105 		return detail::policy_cons<detail::dependency_policy<A, B>, detail::null_type>();
106 	}
107 
108 	template<int A>
109 	detail::policy_cons<detail::dependency_policy<0, A>, detail::null_type>
return_internal_reference(LUABIND_PLACEHOLDER_ARG (A))110 	return_internal_reference(LUABIND_PLACEHOLDER_ARG(A))
111 	{
112 		return detail::policy_cons<detail::dependency_policy<0, A>, detail::null_type>();
113 	}
114 }
115 
116 #endif
117 
118 #endif // LUABIND_DEPENDENCY_POLICY_HPP_INCLUDED
119 
120