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1 | #if !defined(BOOST_PROTO_DONT_USE_PREPROCESSED_FILES) | |
2 | ||
3 | #include <boost/proto/transform/detail/preprocessed/when.hpp> | |
4 | ||
5 | #elif !defined(BOOST_PP_IS_ITERATING) | |
6 | ||
7 | #if defined(__WAVE__) && defined(BOOST_PROTO_CREATE_PREPROCESSED_FILES) | |
8 | #pragma wave option(preserve: 2, line: 0, output: "preprocessed/when.hpp") | |
9 | #endif | |
10 | ||
11 | /////////////////////////////////////////////////////////////////////////////// | |
12 | /// \file when.hpp | |
13 | /// Definition of when transform. | |
14 | // | |
15 | // Copyright 2008 Eric Niebler. Distributed under the Boost | |
16 | // Software License, Version 1.0. (See accompanying file | |
17 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
18 | ||
19 | #if defined(__WAVE__) && defined(BOOST_PROTO_CREATE_PREPROCESSED_FILES) | |
20 | #pragma wave option(preserve: 1) | |
21 | #endif | |
22 | ||
23 | #define BOOST_PP_ITERATION_PARAMS_1 \ | |
24 | (3, (0, BOOST_PROTO_MAX_ARITY, <boost/proto/transform/detail/when.hpp>)) | |
25 | #include BOOST_PP_ITERATE() | |
26 | ||
27 | #if defined(__WAVE__) && defined(BOOST_PROTO_CREATE_PREPROCESSED_FILES) | |
28 | #pragma wave option(output: null) | |
29 | #endif | |
30 | ||
31 | #else | |
32 | ||
33 | #define N BOOST_PP_ITERATION() | |
34 | ||
35 | /// \brief A grammar element and a PrimitiveTransform that associates | |
36 | /// a transform with the grammar. | |
37 | /// | |
38 | /// Use <tt>when\<\></tt> to override a grammar's default transform | |
39 | /// with a custom transform. It is for used when composing larger | |
40 | /// transforms by associating smaller transforms with individual | |
41 | /// rules in your grammar, as in the following transform which | |
42 | /// counts the number of terminals in an expression. | |
43 | /// | |
44 | /// \code | |
45 | /// // Count the terminals in an expression tree. | |
46 | /// // Must be invoked with initial state == mpl::int_<0>(). | |
47 | /// struct CountLeaves | |
48 | /// : or_< | |
49 | /// when<terminal<_>, mpl::next<_state>()> | |
50 | /// , otherwise<fold<_, _state, CountLeaves> > | |
51 | /// > | |
52 | /// {}; | |
53 | /// \endcode | |
54 | /// | |
55 | /// The <tt>when\<G, R(A0,A1,...)\></tt> form accepts either a | |
56 | /// CallableTransform or an ObjectTransform as its second parameter. | |
57 | /// <tt>when\<\></tt> uses <tt>is_callable\<R\>::value</tt> to | |
58 | /// distinguish between the two, and uses <tt>call\<\></tt> to | |
59 | /// evaluate CallableTransforms and <tt>make\<\></tt> to evaluate | |
60 | /// ObjectTransforms. | |
61 | template<typename Grammar, typename R BOOST_PP_ENUM_TRAILING_PARAMS(N, typename A)> | |
62 | struct when<Grammar, R(BOOST_PP_ENUM_PARAMS(N, A))> | |
63 | : detail::when_impl<Grammar, R, R(BOOST_PP_ENUM_PARAMS(N, A))> | |
64 | {}; | |
65 | ||
66 | #if N > 0 | |
67 | /// \brief A grammar element and a PrimitiveTransform that associates | |
68 | /// a transform with the grammar. | |
69 | /// | |
70 | /// Use <tt>when\<\></tt> to override a grammar's default transform | |
71 | /// with a custom transform. It is for used when composing larger | |
72 | /// transforms by associating smaller transforms with individual | |
73 | /// rules in your grammar, as in the following transform which | |
74 | /// counts the number of terminals in an expression. | |
75 | /// | |
76 | /// \code | |
77 | /// // Count the terminals in an expression tree. | |
78 | /// // Must be invoked with initial state == mpl::int_<0>(). | |
79 | /// struct CountLeaves | |
80 | /// : or_< | |
81 | /// when<terminal<_>, mpl::next<_state>()> | |
82 | /// , otherwise<fold<_, _state, CountLeaves> > | |
83 | /// > | |
84 | /// {}; | |
85 | /// \endcode | |
86 | /// | |
87 | /// The <tt>when\<G, R(A0,A1,...)\></tt> form accepts either a | |
88 | /// CallableTransform or an ObjectTransform as its second parameter. | |
89 | /// <tt>when\<\></tt> uses <tt>is_callable\<R\>::value</tt> to | |
90 | /// distinguish between the two, and uses <tt>call\<\></tt> to | |
91 | /// evaluate CallableTransforms and <tt>make\<\></tt> to evaluate | |
92 | /// ObjectTransforms. | |
93 | template<typename Grammar, typename R BOOST_PP_ENUM_TRAILING_PARAMS(N, typename A)> | |
94 | struct when<Grammar, R(BOOST_PP_ENUM_PARAMS(N, A)...)> | |
95 | : detail::when_impl<Grammar, R, R(BOOST_PP_ENUM_PARAMS(N, A)...)> | |
96 | {}; | |
97 | #endif | |
98 | ||
99 | #undef N | |
100 | ||
101 | #endif |