将C ++类转换为JSON [英] Converting C++ class to JSON

问题描述

我想创建一个包含我类的实例变量的JSON字符串。

例如，

  class Example {
 std :: string string; 
 std :: map< std :: string，std：string>地图; 
 std :: vector< int>向量; 
}; 
  

将成为：

  {
string：the-string-value，
map：{
key1：val1，
key2 ：val2
}，
vector：[1,2,3,4] 
} 
  

我已经研究了几个C ++库来创建JSON，他们都看起来非常复杂。我想要类似于JavaScript的 JSON.stringify（object）。换句话说，只是传递一个std :: map到它并接收一个字符串。地图可以包含其他地图，向量，列表，字符串，数字和布尔。

这是最好的方法是什么？

感谢您的帮助。

编辑 v查看以下内容：

json精神，jsoncpp，zoolib，JOST，CAJUN，libjson，nosjob，JsonBox，jsonme -

我知道我可以在下面的答案中构造一个单独的JSON对象，并转换为JSON我想能够存储我的东西在标准集合和转换。

编辑2

好的，废除了序列化一个类的想法，因为它似乎不可能与C ++缺乏反射。

有一个很好的方法来转换std :: map包含std：maps，std :: vectors，std :: lists，numbers，strings和bools JSON不需要更改数据类型或将数据复制到新数据类型？

谢谢。

解决方案

JSON Spirit 将允许您这样做：

  Object addr_obj; 
 
 addr_obj.push_back（Pair（house_number，42））; 
 addr_obj.push_back（Pair（road，East Street））; 
 addr_obj.push_back（Pair（town，Newtown））; 
 
 ofstream os（address.txt）; 
 write（addr_obj，os，pretty_print）; 
 os.close（）; 
  

输出：

  {
house_number：42，
road：East Street，
town：Newtown
} 
  

json_map_demo.cpp 将是一个很好的开始，我想。

I'd like to create a JSON string containing the instance variables of my class.

For example,

class Example {  
    std::string string;  
    std::map<std::string, std:string> map;  
    std::vector<int> vector;  
};

would become:

{
    "string":"the-string-value",
    "map": {
        "key1":"val1",
        "key2":"val2"
    },
    "vector":[1,2,3,4]
}

I've looked into several C++ libraries for creating JSON and they all seem incredibly complex. I'd like something similar to Javascript's JSON.stringify(object). In other words just pass a std::map to it and receive a string. The map could contain other maps, vectors, lists, strings, numbers and bools.

What's the nicest way to do this?

Thanks for your help.

Edit

I've looked into the following:

json spirit, jsoncpp, zoolib, JOST, CAJUN, libjson, nosjob, JsonBox, jsonme--

Which I understand I can construct a separate JSON object as in an answer below and convert to JSON I'd like to be able to store my stuff in standard collections and convert.

Edit 2

Okay, scrap the idea of serializing a class since it appears that's impossible with C++'s lack of reflection.

Is there a nice way to convert a std::map containing std:maps, std::vectors, std::lists, numbers, strings, and bools to JSON without having to change datatypes or copying data to a new datatype?

Thanks.

解决方案

JSON Spirit would allow you to do it like so:

Object addr_obj;

addr_obj.push_back( Pair( "house_number", 42 ) );
addr_obj.push_back( Pair( "road",         "East Street" ) );
addr_obj.push_back( Pair( "town",         "Newtown" ) );

ofstream os( "address.txt" );
write( addr_obj, os, pretty_print );
os.close();

Output:

{
    "house_number" : 42,
    "road" : "East Street",
    "town" : "Newtown"
}

The json_map_demo.cpp would be a nice place to start, I suppose.

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