1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3 Copyright (c) 2001-2011 Hartmut Kaiser
4
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7=============================================================================*/
8#if !defined(SPIRIT_PASS_CONTAINER_JANUARY_06_2009_0802PM)
9#define SPIRIT_PASS_CONTAINER_JANUARY_06_2009_0802PM
10
11#if defined(_MSC_VER)
12#pragma once
13#endif
14
15#include <boost/spirit/home/qi/detail/attributes.hpp>
16#include <boost/spirit/home/support/container.hpp>
17#include <boost/spirit/home/support/handles_container.hpp>
18#include <boost/type_traits/is_base_of.hpp>
19#include <boost/type_traits/is_convertible.hpp>
20#include <boost/mpl/bool.hpp>
21#include <boost/mpl/and.hpp>
22#include <boost/mpl/or.hpp>
23#include <boost/preprocessor/cat.hpp>
24#include <boost/preprocessor/repetition/repeat.hpp>
25
26namespace boost { namespace spirit { namespace qi { namespace detail
27{
28 // Helper meta-function allowing to evaluate weak substitutability and
29 // negate the result if the predicate (Sequence) is not true
30 template <typename Sequence, typename Attribute, typename ValueType>
31 struct negate_weak_substitute_if_not
32 : mpl::if_<
33 Sequence
34 , typename traits::is_weak_substitute<Attribute, ValueType>::type
35 , typename mpl::not_<
36 traits::is_weak_substitute<Attribute, ValueType>
37 >::type>
38 {};
39
40 // pass_through_container: utility to check decide whether a provided
41 // container attribute needs to be passed through to the current component
42 // or of we need to split the container by passing along instances of its
43 // value type
44
45 // if the expected attribute of the current component is neither a Fusion
46 // sequence nor a container, we will pass through the provided container
47 // only if its value type is not compatible with the component
48 template <typename Container, typename ValueType, typename Attribute
49 , typename Sequence, typename Enable = void>
50 struct pass_through_container_base
51 : negate_weak_substitute_if_not<Sequence, Attribute, ValueType>
52 {};
53
54 // Specialization for fusion sequences, in this case we check whether all
55 // the types in the sequence are convertible to the lhs attribute.
56 //
57 // We return false if the rhs attribute itself is a fusion sequence, which
58 // is compatible with the LHS sequence (we want to pass through this
59 // attribute without it being split apart).
60 template <typename Container, typename ValueType, typename Attribute
61 , typename Sequence = mpl::true_>
62 struct not_compatible_element
63 : mpl::and_<
64 negate_weak_substitute_if_not<Sequence, Attribute, Container>
65 , negate_weak_substitute_if_not<Sequence, Attribute, ValueType> >
66 {};
67
68 // If the value type of the container is not a Fusion sequence, we pass
69 // through the container if each of the elements of the Attribute
70 // sequence is compatible with either the container or its value type.
71 template <typename Container, typename ValueType, typename Attribute
72 , typename Sequence
73 , bool IsSequence = fusion::traits::is_sequence<ValueType>::value>
74 struct pass_through_container_fusion_sequence
75 {
76 typedef typename mpl::find_if<
77 Attribute, not_compatible_element<Container, ValueType, mpl::_1>
78 >::type iter;
79 typedef typename mpl::end<Attribute>::type end;
80
81 typedef typename is_same<iter, end>::type type;
82 };
83
84 // If both, the Attribute and the value type of the provided container
85 // are Fusion sequences, we pass the container only if the two
86 // sequences are not compatible.
87 template <typename Container, typename ValueType, typename Attribute
88 , typename Sequence>
89 struct pass_through_container_fusion_sequence<
90 Container, ValueType, Attribute, Sequence, true>
91 {
92 typedef typename mpl::find_if<
93 Attribute
94 , not_compatible_element<Container, ValueType, mpl::_1, Sequence>
95 >::type iter;
96 typedef typename mpl::end<Attribute>::type end;
97
98 typedef typename is_same<iter, end>::type type;
99 };
100
101 template <typename Container, typename ValueType, typename Attribute
102 , typename Sequence>
103 struct pass_through_container_base<Container, ValueType, Attribute
104 , Sequence
105 , typename enable_if<fusion::traits::is_sequence<Attribute> >::type>
106 : pass_through_container_fusion_sequence<
107 Container, ValueType, Attribute, Sequence>
108 {};
109
110 // Specialization for containers
111 //
112 // If the value type of the attribute of the current component is not
113 // a Fusion sequence, we have to pass through the provided container if
114 // both are compatible.
115 template <typename Container, typename ValueType, typename Attribute
116 , typename Sequence, typename AttributeValueType
117 , bool IsSequence = fusion::traits::is_sequence<AttributeValueType>::value>
118 struct pass_through_container_container
119 : mpl::or_<
120 traits::is_weak_substitute<Attribute, Container>
121 , traits::is_weak_substitute<AttributeValueType, Container> >
122 {};
123
124 // If the value type of the exposed container attribute is a Fusion
125 // sequence, we use the already existing logic for those.
126 template <typename Container, typename ValueType, typename Attribute
127 , typename Sequence, typename AttributeValueType>
128 struct pass_through_container_container<
129 Container, ValueType, Attribute, Sequence, AttributeValueType, true>
130 : pass_through_container_fusion_sequence<
131 Container, ValueType, AttributeValueType, Sequence>
132 {};
133
134 template <typename Container, typename ValueType, typename Attribute
135 , typename Sequence>
136 struct pass_through_container_base<
137 Container, ValueType, Attribute, Sequence
138 , typename enable_if<traits::is_container<Attribute> >::type>
139 : detail::pass_through_container_container<
140 Container, ValueType, Attribute, Sequence
141 , typename traits::container_value<Attribute>::type>
142 {};
143
144 // Specialization for exposed optional attributes
145 //
146 // If the type embedded in the exposed optional is not a Fusion
147 // sequence we pass through the container attribute if it is compatible
148 // either to the optionals embedded type or to the containers value
149 // type.
150 template <typename Container, typename ValueType, typename Attribute
151 , typename Sequence
152 , bool IsSequence = fusion::traits::is_sequence<Attribute>::value>
153 struct pass_through_container_optional
154 : mpl::or_<
155 traits::is_weak_substitute<Attribute, Container>
156 , traits::is_weak_substitute<Attribute, ValueType> >
157 {};
158
159 // If the embedded type of the exposed optional attribute is a Fusion
160 // sequence, we use the already existing logic for those.
161 template <typename Container, typename ValueType, typename Attribute
162 , typename Sequence>
163 struct pass_through_container_optional<
164 Container, ValueType, Attribute, Sequence, true>
165 : pass_through_container_fusion_sequence<
166 Container, ValueType, Attribute, Sequence>
167 {};
168
169 ///////////////////////////////////////////////////////////////////////////
170 template <typename Container, typename ValueType, typename Attribute
171 , typename Sequence>
172 struct pass_through_container
173 : pass_through_container_base<Container, ValueType, Attribute, Sequence>
174 {};
175
176 // Handle optional attributes
177 template <typename Container, typename ValueType, typename Attribute
178 , typename Sequence>
179 struct pass_through_container<
180 Container, ValueType, boost::optional<Attribute>, Sequence>
181 : pass_through_container_optional<
182 Container, ValueType, Attribute, Sequence>
183 {};
184
185 // If both, the containers value type and the exposed attribute type are
186 // optionals we are allowed to pass through the container only if the
187 // embedded types of those optionals are not compatible.
188 template <typename Container, typename ValueType, typename Attribute
189 , typename Sequence>
190 struct pass_through_container<
191 Container, boost::optional<ValueType>, boost::optional<Attribute>
192 , Sequence>
193 : mpl::not_<traits::is_weak_substitute<Attribute, ValueType> >
194 {};
195
196 // Specialization for exposed variant attributes
197 //
198 // We pass through the container attribute if at least one of the embedded
199 // types in the variant requires to pass through the attribute
200
201#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
202 template <typename Container, typename ValueType, typename Sequence
203 , typename T>
204 struct pass_through_container<Container, ValueType, boost::variant<T>
205 , Sequence>
206 : pass_through_container<Container, ValueType, T, Sequence>
207 {};
208
209 template <typename Container, typename ValueType, typename Sequence
210 , typename T0, typename ...TN>
211 struct pass_through_container<Container, ValueType
212 , boost::variant<T0, TN...>, Sequence>
213 : mpl::bool_<pass_through_container<
214 Container, ValueType, T0, Sequence
215 >::type::value || pass_through_container<
216 Container, ValueType, boost::variant<TN...>, Sequence
217 >::type::value>
218 {};
219#else
220#define BOOST_SPIRIT_PASS_THROUGH_CONTAINER(z, N, _) \
221 pass_through_container<Container, ValueType, \
222 BOOST_PP_CAT(T, N), Sequence>::type::value || \
223 /***/
224
225 // make sure unused variant parameters do not affect the outcome
226 template <typename Container, typename ValueType, typename Sequence>
227 struct pass_through_container<Container, ValueType
228 , boost::detail::variant::void_, Sequence>
229 : mpl::false_
230 {};
231
232 template <typename Container, typename ValueType, typename Sequence
233 , BOOST_VARIANT_ENUM_PARAMS(typename T)>
234 struct pass_through_container<Container, ValueType
235 , boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Sequence>
236 : mpl::bool_<BOOST_PP_REPEAT(BOOST_VARIANT_LIMIT_TYPES
237 , BOOST_SPIRIT_PASS_THROUGH_CONTAINER, _) false>
238 {};
239
240#undef BOOST_SPIRIT_PASS_THROUGH_CONTAINER
241#endif
242}}}}
243
244///////////////////////////////////////////////////////////////////////////////
245namespace boost { namespace spirit { namespace traits
246{
247 ///////////////////////////////////////////////////////////////////////////
248 // forwarding customization point for domain qi::domain
249 template <typename Container, typename ValueType, typename Attribute
250 , typename Sequence>
251 struct pass_through_container<
252 Container, ValueType, Attribute, Sequence, qi::domain>
253 : qi::detail::pass_through_container<
254 Container, ValueType, Attribute, Sequence>
255 {};
256}}}
257
258namespace boost { namespace spirit { namespace qi { namespace detail
259{
260 ///////////////////////////////////////////////////////////////////////////
261 // This function handles the case where the attribute (Attr) given
262 // the sequence is an STL container. This is a wrapper around F.
263 // The function F does the actual parsing.
264 template <typename F, typename Attr, typename Sequence>
265 struct pass_container
266 {
267 typedef typename F::context_type context_type;
268 typedef typename F::iterator_type iterator_type;
269
270 pass_container(F const& f_, Attr& attr_)
271 : f(f_), attr(attr_) {}
272
273 // this is for the case when the current element exposes an attribute
274 // which is pushed back onto the container
275 template <typename Component>
276 bool dispatch_container(Component const& component, mpl::false_) const
277 {
278 // synthesized attribute needs to be default constructed
279 typename traits::container_value<Attr>::type val =
280 typename traits::container_value<Attr>::type();
281
282 iterator_type save = f.first;
283 bool r = f(component, val);
284 if (!r)
285 {
286 // push the parsed value into our attribute
287 r = !traits::push_back(attr, val);
288 if (r)
289 f.first = save;
290 }
291 return r;
292 }
293
294 // this is for the case when the current element is able to handle an
295 // attribute which is a container itself, this element will push its
296 // data directly into the attribute container
297 template <typename Component>
298 bool dispatch_container(Component const& component, mpl::true_) const
299 {
300 return f(component, attr);
301 }
302
303 ///////////////////////////////////////////////////////////////////////
304 // this is for the case when the current element doesn't expect an
305 // attribute
306 template <typename Component>
307 bool dispatch_attribute(Component const& component, mpl::false_) const
308 {
309 return f(component, unused);
310 }
311
312 // the current element expects an attribute
313 template <typename Component>
314 bool dispatch_attribute(Component const& component, mpl::true_) const
315 {
316 typedef typename traits::container_value<Attr>::type value_type;
317 typedef typename traits::attribute_of<
318 Component, context_type, iterator_type>::type
319 rhs_attribute;
320
321 // this predicate detects, whether the attribute of the current
322 // element is a substitute for the value type of the container
323 // attribute
324 typedef mpl::and_<
325 traits::handles_container<
326 Component, Attr, context_type, iterator_type>
327 , traits::pass_through_container<
328 Attr, value_type, rhs_attribute, Sequence, qi::domain>
329 > predicate;
330
331 return dispatch_container(component, predicate());
332 }
333
334 // Dispatches to dispatch_main depending on the attribute type
335 // of the Component
336 template <typename Component>
337 bool operator()(Component const& component) const
338 {
339 // we need to dispatch depending on the type of the attribute
340 // of the current element (component). If this is has no attribute
341 // we shouldn't pass an attribute at all.
342 typedef typename traits::not_is_unused<
343 typename traits::attribute_of<
344 Component, context_type, iterator_type
345 >::type
346 >::type predicate;
347
348 // ensure the attribute is actually a container type
349 traits::make_container(attr);
350
351 return dispatch_attribute(component, predicate());
352 }
353
354 F f;
355 Attr& attr;
356
357 private:
358 // silence MSVC warning C4512: assignment operator could not be generated
359 pass_container& operator= (pass_container const&);
360 };
361
362 ///////////////////////////////////////////////////////////////////////////
363 // Utility function to make a pass_container for container components
364 // (kleene, list, plus, repeat)
365 template <typename F, typename Attr>
366 inline pass_container<F, Attr, mpl::false_>
367 make_pass_container(F const& f, Attr& attr)
368 {
369 return pass_container<F, Attr, mpl::false_>(f, attr);
370 }
371
372 // Utility function to make a pass_container for sequences
373 template <typename F, typename Attr>
374 inline pass_container<F, Attr, mpl::true_>
375 make_sequence_pass_container(F const& f, Attr& attr)
376 {
377 return pass_container<F, Attr, mpl::true_>(f, attr);
378 }
379}}}}
380
381#endif
382
383

source code of qtlocation/src/3rdparty/mapbox-gl-native/deps/boost/1.65.1/include/boost/spirit/home/qi/detail/pass_container.hpp