C++：如何使用boost :: property_tree創建一個數組？

Question

我看不到使用boost :: property樹創建數組的方法。下面的代碼...

#include <boost/property_tree/ptree.hpp> 
#include <boost/property_tree/json_parser.hpp> 

#include <iostream> 

int main() 
{ 
    try { 
    boost::property_tree::ptree props; 
    props.push_back(std::make_pair("foo", "bar")); 
    props.push_back(std::make_pair("foo", "baz")); 
    boost::property_tree::write_json("prob.json", props); 
    } catch (const std::exception & ex) { 
    std::cout << ex.what() << std::endl; 
    } 
} 

...只是給了我......

{ 
    "foo": "bar", 
    "foo": "baz" 
} 

上的boost :: property_tree該文檔是稀疏。如何用boost :: property_tree創建JSON數組？

Answer 1

如果你有一個子樹，其唯一的節點具有空鍵，那麼它將被序列化爲一個數組：

boost::property_tree::ptree array; 
array.push_back(std::make_pair("", "bar")); 
array.push_back(std::make_pair("", "baz")); 

boost::property_tree::ptree props; 
props.push_back(std::make_pair("array", array)); 

boost::property_tree::write_json("prob.json", props);