ceph/src/boost/libs/spirit/test/x3/rule3.cpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2012 Joel de Guzman
   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
   8 #include <boost/detail/lightweight_test.hpp>
   9 #include <boost/spirit/home/x3.hpp>
  10 #include <boost/fusion/include/std_pair.hpp>
  11
  12 #include <string>
  13 #include <cstring>
  14 #include <iostream>
  15 #include "test.hpp"
  16
  17 using boost::spirit::x3::_val;
  18
  19 struct f
  20 {
  21     template <typename Context>
  22     void operator()(Context const& ctx) const
  23     {
  24         _val(ctx) += _attr(ctx);
  25     }
  26 };
  27
  28
  29 struct stationary : boost::noncopyable
  30 {
  31     explicit stationary(int i) : val{i} {}
  32     stationary& operator=(int i) { val = i; return *this; }
  33
  34     int val;
  35 };
  36
  37
  38 namespace check_stationary {
  39
  40 boost::spirit::x3::rule<class a_r, stationary> const a;
  41 boost::spirit::x3::rule<class b_r, stationary> const b;
  42
  43 auto const a_def = '{' >> boost::spirit::x3::int_ >> '}';
  44 auto const b_def = a;
  45
  46 BOOST_SPIRIT_DEFINE(a, b)
  47
  48 }
  49
  50
  51 int main()
  52 {
  53     using spirit_test::test_attr;
  54     using spirit_test::test;
  55
  56     using namespace boost::spirit::x3::ascii;
  57     using boost::spirit::x3::rule;
  58     using boost::spirit::x3::lit;
  59     using boost::spirit::x3::eps;
  60     using boost::spirit::x3::unused_type;
  61
  62
  63     { // synth attribute value-init
  64
  65         std::string s;
  66         typedef rule<class r, std::string> rule_type;
  67
  68         auto rdef = rule_type()
  69             = alpha                 [f()]
  70             ;
  71
  72         BOOST_TEST(test_attr("abcdef", +rdef, s));
  73         BOOST_TEST(s == "abcdef");
  74     }
  75
  76     { // synth attribute value-init
  77
  78         std::string s;
  79         typedef rule<class r, std::string> rule_type;
  80
  81         auto rdef = rule_type() =
  82             alpha /
  83                [](auto& ctx)
  84                {
  85                   _val(ctx) += _attr(ctx);
  86                }
  87             ;
  88
  89         BOOST_TEST(test_attr("abcdef", +rdef, s));
  90         BOOST_TEST(s == "abcdef");
  91     }
  92
  93     {
  94         auto r = rule<class r, int>{} = eps[([] (auto& ctx) {
  95             using boost::spirit::x3::_val;
  96             static_assert(std::is_same<std::decay_t<decltype(_val(ctx))>, unused_type>::value,
  97                 "Attribute must not be synthesized");
  98         })];
  99         BOOST_TEST(test("", r));
 100     }
 101
 102     { // ensure no unneded synthesization, copying and moving occured
 103         stationary st { 0 };
 104         BOOST_TEST(test_attr("{42}", check_stationary::b, st));
 105         BOOST_TEST_EQ(st.val, 42);
 106     }
 107
 108     return boost::report_errors();
 109 }