使用 BOOST_FUSION_ADAPT_ADT 调整 class 时出错

Question

我有以下 class:

#ifndef WFRACTAL_FRACTAL_METADATA_H_
#define WFRACTAL_FRACTAL_METADATA_H_

#include <string>

namespace WFractal {
namespace Fractal {

class Metadata {

public:

    void setAuthorName(const std::string &name);
    void setAuthorEMail(const std::string &email);
    void setBriefDescription(const std::string &brief);
    void setCompleteDescription(const std::string &description);
    std::string getAuthorName() const;
    std::string getAuthorEMail() const;
    std::string getBriefDescription() const;
    std::string getCompleteDescription() const;

public:

    bool operator==(const Metadata &other);

private:

    std::string m_name;
    std::string m_email;
    std::string m_brief;
    std::string m_description;
};

} // namespace Fractal
} // namespace WFractal

#endif // !WFRACTAL_FRACTAL_METADATA_H_

我想使用 boost::spirit 从以下文件内容中解析它：

metadata {
  author = "Me";
  email = "myemail";
  brief = "brief description";
  description = "complete description";
}

我从 this page 那里了解到我可以使用 BOOST_FUSION_ADAPT_STRUCT 来解析它。这是我的语法模板：

#ifndef WFRACTAL_FRACTAL_PARSER_METADATAGRAMMAR_H_
#define WFRACTAL_FRACTAL_PARSER_METADATAGRAMMAR_H_

#include <boost/fusion/adapted/adt/adapt_adt.hpp>
#include <boost/fusion/include/adapt_adt.hpp>
#include <boost/spirit/include/qi_no_case.hpp>
#include <string>
#include "Fractal/Metadata.h"

BOOST_FUSION_ADAPT_ADT(
    WFractal::Fractal::Metadata,
    (obj.getAuthorName(), obj.setAuthorName(val))
    (obj.getAuthorEMail(), obj.setBriefDescription(val))
    (obj.getBriefDescription(), obj.setCompleteDescription(val))
    (obj.getCompleteDescription(), obj.setAuthorEMail(val))
)

namespace WFractal {
namespace Fractal {
namespace Parser {

template <typename Iterator>
struct MetadataParser : boost::spirit::qi::grammar<Iterator, Metadata(), boost::spirit::ascii::space_type> {
    MetadataParser() : MetadataParser::base_type(start) {
        using boost::spirit::qi::int_;
        using boost::spirit::qi::lit;
        using boost::spirit::qi::double_;
        using boost::spirit::qi::lexeme;
        using boost::spirit::ascii::char_;
        using boost::spirit::ascii::no_case;

        quoted_string %= lexeme['"' >> +(char_ - '"') >> '"'];

        start %=
        no_case[lit("metadata")]
        >> '{'
        >>  no_case[lit("author")] >> '=' >> quoted_string >> ';'
        >>  no_case[lit("email")] >> '=' >> quoted_string >> ';'
        >>  no_case[lit("brief")] >> '=' >> quoted_string >> ';'
        >>  no_case[lit("description")] >> '=' >> quoted_string >> ';'
        >>  '}'
        ;
    }

    boost::spirit::qi::rule<Iterator, std::string(), boost::spirit::ascii::space_type> quoted_string;
    boost::spirit::qi::rule<Iterator, Metadata(), boost::spirit::ascii::space_type> start;
};

} // namespace Parser
} // namespace Fractal
} // namespace WFractal

#endif // !WFRACTAL_FRACTAL_PARSER_METADATAGRAMMAR_H_

当我创建此语法的实例时（始终遵循页面示例），我得到编译器错误：

typedef string::const_iterator StringIterator;
typedef Parser::MetadataParser<StringIterator> MetadataParser;
MetadataParser parser;

我遇到了很多错误（boost 的典型错误...）并且我注意到其中有许多此错误的副本：

src/Fractal/FileFactory.cpp:27:17:   required from here
/usr/include/boost/spirit/home/qi/detail/assign_to.hpp:152:18: error: no matching function for call to ‘boost::fusion::extension::adt_attribute_proxy<WFractal::Fractal::Metadata, 0, false>::adt_attribute_proxy(const std::__cxx11::basic_string<char>&)’
             attr = static_cast<Attribute>(val);

我做错了什么？我该如何解决？

编辑

正如 m.s 所建议的那样。我添加了 #include <boost/spirit/include/support_adapt_adt_attributes.hpp> header 但这不起作用。

#ifndef WFRACTAL_FRACTAL_PARSER_METADATAPARSER_H_
#define WFRACTAL_FRACTAL_PARSER_METADATAPARSER_H_

#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_object.hpp>
#include <boost/fusion/include/io.hpp>
#include <boost/fusion/adapted/adt/adapt_adt.hpp>
#include <boost/fusion/include/adapt_adt.hpp>
#include <boost/spirit/include/support_adapt_adt_attributes.hpp>
#include <string>
#include "Fractal/Metadata.h"

BOOST_FUSION_ADAPT_ADT(
    WFractal::Fractal::Metadata,
    (obj.getAuthorName(), obj.setAuthorName(val))
    (obj.getAuthorEMail(), obj.setAuthorEMail(val))
    (obj.getBriefDescription(), obj.setBriefDescription(val))
    (obj.getCompleteDescription(), obj.setCompleteDescription(val))
)

namespace WFractal {
namespace Fractal {
namespace Parser {

template <typename Iterator>
struct MetadataParser : boost::spirit::qi::grammar<Iterator, Metadata(), boost::spirit::ascii::space_type> {
    MetadataParser() : MetadataParser::base_type(start) {
        using boost::spirit::qi::lit;
        using boost::spirit::qi::lexeme;
        using boost::spirit::ascii::char_;
        using boost::spirit::ascii::no_case;

        quoted_string %= lexeme['"' >> +(char_ - '"') >> '"'];

        start %=
        no_case[lit("metadata")]
        >> '{'
        >> ((no_case[lit("author")] >> '=' >> quoted_string >> ';')
        ^  (no_case[lit("email")] >> '=' >> quoted_string >> ';')
        ^  (no_case[lit("brief")] >> '=' >> quoted_string >> ';')
        ^  (no_case[lit("description")] >> '=' >> quoted_string >> ';'))
        >>  '}'
        ;
    }

    boost::spirit::qi::rule<Iterator, std::string(), boost::spirit::ascii::space_type> quoted_string;
    boost::spirit::qi::rule<Iterator, Metadata(), boost::spirit::ascii::space_type> start;
};

} // namespace Parser
} // namespace Fractal
} // namespace WFractal

#endif // !WFRACTAL_FRACTAL_PARSER_METADATAPARSER_H_

Answer 1

嗯。

经过与 Modular Boost 的长期斗争和 git...我发现这是一种回归。

此拉取请求已部分修复回归：

reenabled support for BOOST_FUSION_ADAPT_ADT adapted structs #153

可悲的是，它在排列解析器的存在下仍然被破坏。我已经用 BOOST_FUSION_ADAPT_STRUCT 进行了测试，以验证它没有以其他方式损坏。

我会将缩减的示例添加到 PR 以征求意见。同时，这里是自包含的复制器：

Live On Coliru

#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/adapted.hpp>
#include <iostream>

class Foo {
  public:
    char const& getA() const { return a; } 
    char const& getB() const { return b; } 

    void setA(char value)    { a = value; } 
    void setB(char value)    { b = value; } 
  private:
    char a, b;
};

BOOST_FUSION_ADAPT_ADT(
        Foo,
        (char const&, char const&, obj.getA(), obj.setA(val))
        (char const&, char const&, obj.getB(), obj.setB(val))
    )


int main() {
    namespace qi = boost::spirit::qi;

    boost::spirit::istream_iterator f(std::cin), l; // input e.g. "a=a;b=b;"
    Foo foo;

    bool r = qi::parse(f, l,
#if 0 // FAILS TO COMPILE
                      ("a=" >> qi::char_ >> ';')
                    ^ ("b=" >> qi::char_ >> ';')
#else // COMPILES WITH FIX FROM PR #153
                      ("a=" >> qi::char_ >> ';')
                   >> ("b=" >> qi::char_ >> ';')
#endif 
                , foo);

    if (r)
        std::cout << "Parsed: " << boost::fusion::as_vector(foo) << "\n";
    else
        std::cerr << "Parse failed\n";
}

但是，如果您将 #if 1 更改为 #if 0，您将得到输出：

Parsed: (a b)

Note of course that's assuming you use a branch that has the PR 153 applied.

使用 BOOST_FUSION_ADAPT_ADT 调整 class 时出错

Error when adapting a class with BOOST_FUSION_ADAPT_ADT

c++

grammar

boost

boost-spirit