Boost Spirit:错误C2664,无法转换'const boost :: phoenix :: actor< Eval>'到'char' [英] Boost Spirit: Error C2664, Cannot convert 'const boost::phoenix::actor<Eval>' to 'char'
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问题描述
我刚开始使用Boost Spirit,并尝试使用Boost Spirit 2.4.2(Boost 1.46.1)编写JSON解析器。对于下面的代码,当尝试执行语义操作/属性时,我得到错误:
I'm new to Boost Spirit and trying to write JSON parser using Boost Spirit 2.4.2 (Boost 1.46.1). For the code below, I get the error when trying to execute semantic action/attribute:
Error 1 error C2664: 'void (char)' : cannot convert parameter 1 from 'const boost::phoenix::actor<Eval>' to 'char'
我看到一些问题,但他们不真的适用于我的情况。请衷心的帮助。谢谢!
I saw some questions but they don't really apply to my case. Please kindly help. Thank you!
#include <map>
#include <string>
#include <vector>
#include <iostream>
#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix_core.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
#include <boost/spirit/include/phoenix_stl.hpp>
#include <boost/spirit/include/phoenix_object.hpp>
#include <boost/spirit/include/phoenix_container.hpp>
#include <boost/spirit/include/phoenix_function.hpp>
#include <boost/spirit/include/phoenix_fusion.hpp>
#include <boost/fusion/include/adapt_assoc_struct.hpp>
#include <boost/fusion/include/io.hpp>
#include <boost/bind.hpp>
#include <boost/function.hpp>
namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
namespace phoenix = boost::phoenix;
void print_char(char c)
{
std::cout << c;
}
template <typename Iterator>
struct json_grammar : qi::grammar<Iterator, ascii::space_type>
{
json_grammar() : json_grammar::base_type(start)
{
using ascii::alpha;
using ascii::alnum;
using qi::long_long;
using qi::long_double;
using qi::lit;
using qi::char_;
using qi::lexeme;
typedef boost::function<void(char)> char_action_t;
//char_action_t beginObj (boost::bind(&print_char, qi::_1));
//
start =
char_('{') [boost::bind(&print_char, qi::_1)]
>> -(js_member % ',')
>> char_('}')
;
//
js_member =
js_key
>> ':' >> js_value
;
//
js_key = (alpha >> *alnum) | js_string
;
//
js_string = js_single_quoted_str | js_double_quoted_str
;
//
js_array = lit('[') >> -(js_value % ',') >> lit(']')
;
//
js_bool = lit("true") | lit("false")
;
//
js_null = lit("null")
;
//
js_value = js_string | js_num | js_array | start | js_bool | js_null | js_empty_str;
//
js_single_quoted_str = (lexeme["'" >> +((char_ | ' ' | "\t") - "'") >> "'"]);
//
js_double_quoted_str = (lexeme['"' >> +((char_ | ' ' | "\t") - '"') >> '"']);
//
js_empty_str = lit("''") | lit("\"\"");
//
js_num = long_long | long_double;
}
qi::rule<Iterator, ascii::space_type> start;
qi::rule<Iterator, ascii::space_type> js_member;
qi::rule<Iterator, ascii::space_type> js_key;
qi::rule<Iterator, ascii::space_type> js_value;
qi::rule<Iterator, ascii::space_type> js_string;
qi::rule<Iterator, ascii::space_type> js_single_quoted_str;
qi::rule<Iterator, ascii::space_type> js_double_quoted_str;
qi::rule<Iterator, ascii::space_type> js_empty_str;
qi::rule<Iterator, ascii::space_type> js_array;
qi::rule<Iterator, ascii::space_type> js_num;
qi::rule<Iterator, ascii::space_type> js_null;
qi::rule<Iterator, ascii::space_type> js_bool;
};
int main()
{
std::string inputStr;
json_grammar<std::string::const_iterator> jsonParser;
bool parseOK = false;
while(std::getline(std::cin, inputStr)) {
if(inputStr.empty() || inputStr[0] == 'q' || inputStr[0] == 'Q')
break;
std::string::const_iterator iter = inputStr.begin();
std::string::const_iterator iterEnd = inputStr.end();
parseOK = qi::phrase_parse(iter, iterEnd, jsonParser, ascii::space);
if(parseOK && iter == iterEnd) {
std::cout << "Successfully parsed the input as JSON!" << std::endl;
} else {
std::cout << "Cannot parse the input as JSON!" << std::endl;
}
}
return 0;
}
推荐答案
更新更新:
Kostya有一个好点,'half'触及基础: boost :: bind
实际上很好,只是使用不同的占位符:
Kostya has a good point and 'half' touches base: boost::bind
actually is fine, just use different placeholders :
[ boost::bind(&print_char, ::_1) ]
[ phoenix::bind(&print_char, qi::_1) ]
[ print_char ]
但不混合:)
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