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  1. #include <iostream>
  2. #include <string>
  3. #include <array>
  4. #include <boost/spirit/include/qi.hpp>
  5. #include <boost/fusion/adapted/struct/adapt_struct.hpp>
  6. #include <boost/fusion/include/adapt_struct.hpp>
  7.  
  8. namespace qi = boost::spirit::qi;
  9. namespace ascii = boost::spirit::ascii;
  10.  
  11.  
  12. // ...code from http://w...content-available-to-author-only...t.org/doc/libs/1_60_0/libs/spirit/example/qi/boost_array.cpp here
  13. ////////////////////////////////////////////////////////////////////////////////////////////////
  14.  
  15. namespace detail
  16. {
  17. 	template <typename T>
  18. 	struct adapt_array;
  19.  
  20. 	template <typename T, std::size_t N>
  21. 	struct adapt_array<std::array<T, N> >
  22. 	{
  23. 		typedef std::array<T, N> array_type;
  24.  
  25. 		adapt_array(array_type& arr)
  26. 			: arr_(arr), current_(0) {}
  27.  
  28. 		// expose a push_back function compatible with std containers
  29. 		bool push_back(typename array_type::value_type const& val)
  30. 		{
  31. 			// if the array is full, we need to bail out
  32. 			// returning false will fail the parse
  33. 			if (current_ >= N)
  34. 				return false;
  35.  
  36. 			arr_[current_++] = val;
  37. 			return true;
  38. 		}
  39.  
  40. 		array_type& arr_;
  41. 		std::size_t current_;
  42. 	};
  43. }
  44.  
  45. namespace result_of
  46. {
  47. 	template <typename T>
  48. 	struct adapt_array;
  49.  
  50. 	template <typename T, std::size_t N>
  51. 	struct adapt_array<std::array<T, N> >
  52. 	{
  53. 		typedef detail::adapt_array<std::array<T, N> > type;
  54. 	};
  55. }
  56.  
  57. template <typename T, std::size_t N>
  58. inline detail::adapt_array<std::array<T, N> >
  59. adapt_array(std::array<T, N>& arr)
  60. {
  61. 	return detail::adapt_array<std::array<T, N> >(arr);
  62. }
  63.  
  64.  
  65. // specialize Spirit's container specific customization points for our adaptor
  66. namespace boost { namespace spirit { namespace traits
  67. {
  68.     template <typename T, std::size_t N>
  69.      struct is_container<::detail::adapt_array<std::array<T, N> > >
  70.        : boost::mpl::true_
  71.      {};
  72.  
  73.     template <typename T, std::size_t N>
  74.     struct container_value<::detail::adapt_array<std::array<T, N> > >
  75.     {
  76.         typedef T type;     // value type of container
  77.     };
  78.  
  79.     template <typename T, std::size_t N>
  80.     struct push_back_container<
  81. 		::detail::adapt_array<std::array<T, N> >, T>
  82.     {
  83.         static bool call(::detail::adapt_array<std::array<T, N> >& c
  84.           , T const& val)
  85.         {
  86.             return c.push_back(val);
  87.         }
  88.     };
  89. }}}
  90.  
  91.  
  92. // test
  93.  
  94. typedef result_of::adapt_array<std::array<double, 6> >::type AdaptedArrayType;
  95.  
  96. struct StructWithArray
  97. {
  98. 	StructWithArray()
  99. 		: adaptedAry_(ary_)
  100. 	{}
  101.  
  102. 	double dummy_; // see http://stackoverflow.com/questions/19823413/spirit-qi-attribute-propagation-issue-with-single-member-struct
  103. 	std::array<double, 6> ary_;
  104. 	AdaptedArrayType adaptedAry_;
  105. };
  106.  
  107. BOOST_FUSION_ADAPT_STRUCT(
  108. 	StructWithArray
  109. 	,
  110. 	(double, dummy_)
  111. 	(AdaptedArrayType, adaptedAry_)
  112. 	)
  113.  
  114. 	template <typename Iterator, typename Skipper>
  115. struct StructWithArrayParser
  116. 	: qi::grammar<Iterator, StructWithArray(), Skipper>
  117. {
  118. 	StructWithArrayParser() : StructWithArrayParser::base_type(start)
  119. 	{
  120. 		using qi::double_;
  121.  
  122. 		arrayLine %= double_ > double_ > double_ > double_ > double_ > double_;
  123. 		start %= double_ > arrayLine;
  124. 	}
  125.  
  126. 	qi::rule<Iterator, AdaptedArrayType(), Skipper> arrayLine;
  127. 	qi::rule<Iterator, StructWithArray(), Skipper> start;
  128. };
  129.  
  130. int main() {
  131. 	std::string arrayStr = "0 1 2 3 4 5 6";
  132. 	std::string::const_iterator it = arrayStr.begin();
  133. 	std::string::const_iterator endIt = arrayStr.end();
  134. 	StructWithArrayParser<std::string::const_iterator, ascii::space_type> grammar;
  135. 	StructWithArray structWithArray;
  136. 	bool ret = phrase_parse(it, endIt, grammar, ascii::space, structWithArray);
  137. 	std::cout << ret << " " << structWithArray.ary_[0] << " " << structWithArray.ary_[5];
  138. 	return 0;
  139. }
  140.  
Success #stdin #stdout 0s 3472KB
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https://ideone.com/7RzSHt
http://stackoverflow.com/questions/34435150/boostspirit-parsing-into-struct-with-stdarray
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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