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1 | /////////////////////////////////////////////////////////////////////////////// |
2 | // quant_style.hpp | |
3 | // | |
4 | // Copyright 2008 Eric Niebler. Distributed under the Boost | |
5 | // Software License, Version 1.0. (See accompanying file | |
6 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
7 | ||
8 | #ifndef BOOST_XPRESSIVE_DETAIL_CORE_QUANT_STYLE_HPP_EAN_10_04_2005 | |
9 | #define BOOST_XPRESSIVE_DETAIL_CORE_QUANT_STYLE_HPP_EAN_10_04_2005 | |
10 | ||
11 | // MS compatible compilers support #pragma once | |
12 | #if defined(_MSC_VER) | |
13 | # pragma once | |
14 | #endif | |
15 | ||
16 | #include <boost/config.hpp> | |
17 | #include <boost/mpl/has_xxx.hpp> | |
18 | #include <boost/xpressive/detail/utility/width.hpp> | |
19 | #include <boost/xpressive/detail/detail_fwd.hpp> | |
20 | ||
21 | namespace boost { namespace xpressive { namespace detail | |
22 | { | |
23 | ||
24 | BOOST_MPL_HAS_XXX_TRAIT_DEF(is_boost_xpressive_xpression_) | |
25 | ||
26 | /////////////////////////////////////////////////////////////////////////////// | |
27 | // is_xpr | |
28 | // | |
29 | template<typename Xpr> | |
30 | struct is_xpr | |
31 | : has_is_boost_xpressive_xpression_<Xpr> | |
32 | {}; | |
33 | ||
34 | /////////////////////////////////////////////////////////////////////////////// | |
35 | // quant_enum | |
36 | // | |
37 | enum quant_enum | |
38 | { | |
39 | quant_none, | |
40 | quant_fixed_width, | |
41 | quant_variable_width | |
42 | }; | |
43 | ||
44 | /////////////////////////////////////////////////////////////////////////////// | |
45 | // quant_style | |
46 | // | |
47 | template<quant_enum QuantStyle, std::size_t Width = unknown_width::value, bool Pure = true> | |
48 | struct quant_style | |
49 | { | |
50 | typedef void is_boost_xpressive_xpression_; | |
51 | ||
52 | // Which quantification strategy to use? | |
53 | BOOST_STATIC_CONSTANT(int, quant = QuantStyle); | |
54 | ||
55 | // how many characters this matcher consumes | |
56 | BOOST_STATIC_CONSTANT(std::size_t, width = Width); | |
57 | ||
58 | // whether this matcher has observable side-effects | |
59 | BOOST_STATIC_CONSTANT(bool, pure = Pure); | |
60 | ||
61 | static detail::width get_width() | |
62 | { | |
63 | return width; | |
64 | } | |
65 | }; | |
66 | ||
67 | #define BOOST_XPR_QUANT_STYLE(Style, Width, Pure) \ | |
68 | typedef void is_boost_xpressive_xpression_; \ | |
69 | BOOST_STATIC_CONSTANT(int, quant = Style); \ | |
70 | BOOST_STATIC_CONSTANT(std::size_t, width = Width); \ | |
71 | BOOST_STATIC_CONSTANT(bool, pure = Pure); \ | |
72 | static detail::width get_width() { return width; } \ | |
73 | /**/ | |
74 | ||
75 | // // Replace transmogrify stupidity with rebindable matchers/placeholders | |
76 | //#define BOOST_XPR_IDENTITY_REBIND(TYPE) \/ | |
77 | // template<typename BidiIter, typename ICase, typename Traits> \/ | |
78 | // struct rebind \/ | |
79 | // { \/ | |
80 | // typedef TYPE type; \/ | |
81 | // }; \/ | |
82 | // /**/ | |
83 | ||
84 | /////////////////////////////////////////////////////////////////////////////// | |
85 | // quant_style_none | |
86 | // this sub-expression cannot be quantified | |
87 | typedef quant_style<quant_none> quant_style_none; | |
88 | ||
89 | /////////////////////////////////////////////////////////////////////////////// | |
90 | // quant_style_fixed_unknown_width | |
91 | // this sub-expression is fixed width for the purpose of quantification, but | |
92 | // the width cannot be determined at compile time. An example would be the | |
93 | // string_matcher or the mark_matcher. | |
94 | typedef quant_style<quant_fixed_width> quant_style_fixed_unknown_width; | |
95 | ||
96 | /////////////////////////////////////////////////////////////////////////////// | |
97 | // quant_style_variable_width | |
98 | // this sub-expression can match a variable number of characters | |
99 | typedef quant_style<quant_variable_width> quant_style_variable_width; | |
100 | ||
101 | /////////////////////////////////////////////////////////////////////////////// | |
102 | // quant_style_fixed_width | |
103 | // for when the sub-expression has a fixed width that is known at compile time | |
104 | template<std::size_t Width> | |
105 | struct quant_style_fixed_width | |
106 | : quant_style<quant_fixed_width, Width> | |
107 | { | |
108 | }; | |
109 | ||
110 | /////////////////////////////////////////////////////////////////////////////// | |
111 | // quant_style_assertion | |
112 | // a zero-width assertion. | |
113 | struct quant_style_assertion | |
114 | : quant_style<quant_none, 0> | |
115 | { | |
116 | }; | |
117 | ||
118 | /////////////////////////////////////////////////////////////////////////////// | |
119 | // quant_type | |
120 | // | |
121 | template<typename Matcher> | |
122 | struct quant_type | |
123 | : mpl::int_<Matcher::quant> | |
124 | { | |
125 | }; | |
126 | ||
127 | }}} // namespace boost::xpressive::detail | |
128 | ||
129 | #endif |