1 | // -- Boost Lambda Library - actions.hpp ---------------------------------- |
2 | |
3 | // Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi) |
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 | // For more information, see www.boost.org |
10 | |
11 | // ---------------------------------------------------------------- |
12 | |
13 | #ifndef BOOST_LAMBDA_ACTIONS_HPP |
14 | #define BOOST_LAMBDA_ACTIONS_HPP |
15 | |
16 | namespace boost { |
17 | namespace lambda { |
18 | |
19 | |
20 | |
21 | template<int Arity, class Act> class action; |
22 | |
23 | // these need to be defined here, since the corresponding lambda |
24 | // functions are members of lambda_functor classes |
25 | |
26 | class assignment_action {}; |
27 | class subscript_action {}; |
28 | |
29 | template <class Action> class other_action; |
30 | |
31 | // action for specifying the explicit return type |
32 | template <class RET> class explicit_return_type_action {}; |
33 | |
34 | // action for preventing the expansion of a lambda expression |
35 | struct protect_action {}; |
36 | |
37 | // must be defined here, comma is a special case |
38 | struct comma_action {}; |
39 | |
40 | |
41 | // actions, for which the existence of protect is checked in return type |
42 | // deduction. |
43 | |
44 | template <class Action> struct is_protectable { |
45 | BOOST_STATIC_CONSTANT(bool, value = false); |
46 | }; |
47 | |
48 | // NOTE: comma action is protectable. Other protectable actions |
49 | // are listed in operator_actions.hpp |
50 | |
51 | template<> struct is_protectable<other_action<comma_action> > { |
52 | BOOST_STATIC_CONSTANT(bool, value = true); |
53 | }; |
54 | |
55 | |
56 | namespace detail { |
57 | |
58 | // this type is used in return type deductions to signal that deduction |
59 | // did not find a result. It does not necessarily mean an error, it commonly |
60 | // means that something else should be tried. |
61 | class unspecified {}; |
62 | } |
63 | |
64 | // function action is a special case: bind functions can be called with |
65 | // the return type specialized explicitly e.g. bind<int>(foo); |
66 | // If this call syntax is used, the return type is stored in the latter |
67 | // argument of function_action template. Otherwise the argument gets the type |
68 | // 'unspecified'. |
69 | // This argument is only relevant in the return type deduction code |
70 | template <int I, class Result_type = detail::unspecified> |
71 | class function_action {}; |
72 | |
73 | template<class T> class function_action<1, T> { |
74 | public: |
75 | template<class RET, class A1> |
76 | static RET apply(A1& a1) { |
77 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
78 | template apply<RET>(a1); |
79 | } |
80 | }; |
81 | |
82 | template<class T> class function_action<2, T> { |
83 | public: |
84 | template<class RET, class A1, class A2> |
85 | static RET apply(A1& a1, A2& a2) { |
86 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
87 | template apply<RET>(a1, a2); |
88 | } |
89 | }; |
90 | |
91 | template<class T> class function_action<3, T> { |
92 | public: |
93 | template<class RET, class A1, class A2, class A3> |
94 | static RET apply(A1& a1, A2& a2, A3& a3) { |
95 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
96 | template apply<RET>(a1, a2, a3); |
97 | } |
98 | }; |
99 | |
100 | template<class T> class function_action<4, T> { |
101 | public: |
102 | template<class RET, class A1, class A2, class A3, class A4> |
103 | static RET apply(A1& a1, A2& a2, A3& a3, A4& a4) { |
104 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
105 | template apply<RET>(a1, a2, a3, a4); |
106 | } |
107 | }; |
108 | |
109 | template<class T> class function_action<5, T> { |
110 | public: |
111 | template<class RET, class A1, class A2, class A3, class A4, class A5> |
112 | static RET apply(A1& a1, A2& a2, A3& a3, A4& a4, A5& a5) { |
113 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
114 | template apply<RET>(a1, a2, a3, a4, a5); |
115 | } |
116 | }; |
117 | |
118 | template<class T> class function_action<6, T> { |
119 | public: |
120 | template<class RET, class A1, class A2, class A3, class A4, class A5, |
121 | class A6> |
122 | static RET apply(A1& a1, A2& a2, A3& a3, A4& a4, A5& a5, A6& a6) { |
123 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
124 | template apply<RET>(a1, a2, a3, a4, a5, a6); |
125 | } |
126 | }; |
127 | |
128 | template<class T> class function_action<7, T> { |
129 | public: |
130 | template<class RET, class A1, class A2, class A3, class A4, class A5, |
131 | class A6, class A7> |
132 | static RET apply(A1& a1, A2& a2, A3& a3, A4& a4, A5& a5, A6& a6, A7& a7) { |
133 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
134 | template apply<RET>(a1, a2, a3, a4, a5, a6, a7); |
135 | } |
136 | }; |
137 | |
138 | template<class T> class function_action<8, T> { |
139 | public: |
140 | template<class RET, class A1, class A2, class A3, class A4, class A5, |
141 | class A6, class A7, class A8> |
142 | static RET apply(A1& a1, A2& a2, A3& a3, A4& a4, A5& a5, A6& a6, A7& a7, |
143 | A8& a8) { |
144 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
145 | template apply<RET>(a1, a2, a3, a4, a5, a6, a7, a8); |
146 | } |
147 | }; |
148 | |
149 | template<class T> class function_action<9, T> { |
150 | public: |
151 | template<class RET, class A1, class A2, class A3, class A4, class A5, |
152 | class A6, class A7, class A8, class A9> |
153 | static RET apply(A1& a1, A2& a2, A3& a3, A4& a4, A5& a5, A6& a6, A7& a7, |
154 | A8& a8, A9& a9) { |
155 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
156 | template apply<RET>(a1, a2, a3, a4, a5, a6, a7, a8, a9); |
157 | } |
158 | }; |
159 | |
160 | template<class T> class function_action<10, T> { |
161 | public: |
162 | template<class RET, class A1, class A2, class A3, class A4, class A5, |
163 | class A6, class A7, class A8, class A9, class A10> |
164 | static RET apply(A1& a1, A2& a2, A3& a3, A4& a4, A5& a5, A6& a6, A7& a7, |
165 | A8& a8, A9& a9, A10& a10) { |
166 | return function_adaptor<typename boost::remove_cv<A1>::type>:: |
167 | template apply<RET>(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10); |
168 | } |
169 | }; |
170 | |
171 | } // namespace lambda |
172 | } // namespace boost |
173 | |
174 | #endif |
175 | |