boost::spirit::qi::phrase_parser() 变成 std::map 错误

Question

下面的代码是将"key=val;.."字符串解析为std::map，编译失败，报错：

Error C2146 : syntax error: missing '>' before identifier 'value_type'
Error C2039 : 'value_type': is not a member of 'std::pair,std::allocator,std::basic_string,std::allocator>>' c:\git\risk-engine-core_tcp\stage\boost-1.66.0-barclays-1\include\boost\spirit\home\support\container.hpp

它不喜欢最后一个参数，"contents" (std::map)，作为容器传递。

Boost 版本为 1.66

namespace qi = boost::spirit::qi;

std::map<std::string,std::string> contents;
std::string::iterator first = str.begin();
std::string::iterator last  = str.end();

const bool result = qi::phrase_parse(first,last, 
*( *(qi::char_-"=")  >> qi::lit("=") >> *(qi::char_-";") >> -qi::lit(";") ),
 ascii::space, contents);

查看 boost 文档和堆栈溢出，我没有发现上述代码有任何问题。

Answer 1

你包括了吗

#include <boost/fusion/adapted/std_pair.hpp>

这是一个包含一些改进建议的工作示例：

Live On Coliru

#include <boost/fusion/adapted/std_pair.hpp>
#include <boost/spirit/include/qi.hpp>
#include <map>
#include <iomanip> // std::quoted

namespace qi = boost::spirit::qi;

int main() {
    std::string str("key = value");
    std::string::const_iterator first = str.begin();
    std::string::const_iterator last  = str.end();

    std::map<std::string, std::string> contents;
    bool const result = qi::phrase_parse(first,last, 
        *( *~qi::char_('=')  >> '=' >> *~qi::char_(';') >> -qi::lit(';') ),
         qi::ascii::space, contents); 

    if (result) {
        std::cout << "Parsed " << contents.size() << " elements\n";
        for (auto& [k,v] : contents) {
            std::cout << "\t" << std::quoted(k) << ": " << std::quoted(v) << "\n";
        }
    } else {
        std::cout << "Parse failed\n";
    }

    if (first != last)
        std::cout << "Remaining input unparsed: " << std::quoted(std::string(first, last)) << "\n";
}

版画

Parsed 1 elements
    "key": "value"

boost::spirit::qi::phrase_parser() 变成 std::map 错误

boost::spirit::qi::phrase_parser() into std::map error

c++

boost-spirit-qi