ceph/src/boost/libs/spirit/test/qi/regression_transform_assignment.cpp

   1 //  Copyright (c) 2001-2011 Hartmut Kaiser
   2 //  Copyright (c) 2011 Dean Michael Berries
   3 //
   4 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include <boost/spirit/include/qi.hpp>
   8
   9 #include <boost/core/lightweight_test.hpp>
  10 #include <boost/fusion/tuple.hpp>
  11 #include <string>
  12
  13 struct foo_parts
  14 {
  15     boost::optional<std::string> first;
  16     std::string second;
  17 };
  18
  19 namespace boost { namespace spirit { namespace traits
  20 {
  21     template <>
  22     struct transform_attribute<foo_parts
  23       , fusion::tuple<std::string &, optional<std::string> &>
  24       , spirit::qi::domain>
  25     {
  26         typedef fusion::tuple<std::string&, optional<std::string>&> type;
  27
  28         static type pre(foo_parts & parts)
  29         {
  30             return fusion::tie(parts.second, parts.first);
  31         }
  32
  33         static void post(foo_parts &, type const &) {}
  34         static void fail(foo_parts &) {}
  35     };
  36 }}}
  37
  38 namespace qi = boost::spirit::qi;
  39
  40 template <typename Iterator>
  41 struct foo_grammar : qi::grammar<Iterator, foo_parts()>
  42 {
  43     foo_grammar() : foo_grammar::base_type(start, "foo")
  44     {
  45         foo_part =
  46                +qi::alpha >> -(+qi::digit)
  47             |   qi::attr(std::string())
  48                 >> qi::attr(boost::optional<std::string>())
  49             ;
  50
  51         start = foo_part.alias();
  52     }
  53
  54     typedef boost::fusion::tuple<std::string&, boost::optional<std::string>&>
  55         tuple_type;
  56
  57     qi::rule<Iterator, tuple_type()> foo_part;
  58     qi::rule<Iterator, foo_parts()> start;
  59 };
  60
  61 int main()
  62 {
  63     foo_parts instance;
  64     foo_grammar<std::string::iterator> grammar;
  65     std::string input = "abc123";
  66
  67     BOOST_TEST(qi::parse(input.begin(), input.end(), grammar, instance) &&
  68         instance.first && instance.first.get() == "123" &&
  69         instance.second == "abc");
  70
  71     return boost::report_errors();
  72 }
  73