Iterating over JSON ptree in boost - c++

Question

I need some help when iterating over JSON ptree in boost. Here's the structure.
{"drives": [{"busy": false, "eof": false, "density": 88 }]}
What I want to do is to print the key and value eg. busy = false. I've tried the code below but there is no output.
BOOST_FOREACH(ptree::value_type &v, pt.get_child("drives"))
{
cout << v.first << endl; // does not work
cout << v.second.data() << endl; // does not work
cout << v.second.get<string>("busy"); // works
}
So how do I print the key?
Thanks in advance for any help.

Answer 1

I went through some old code and I found the way
BOOST_FOREACH(ptree::value_type &v, pt.get_child("drives"))
{
for(auto iter = v.second.begin(); iter!= v.second.end(); ++iter)
{
std::cout << iter->first << " : " << iter->second.get_value<std::string>() << std::endl;
}
}
You only need to iterate over "drives" if you have more than one "drives", and in your json example you don't have.
In your code you try to print v.first and v.data() but those two doesn't hold the data you think they hold.
v.first supposed to hold the key name of "KeyName":{"busy": false, "eof": false, "density": 88 }
which doesn't exists because this value is part of an array.
the v.data() (If I'm not mistaken) holds the key:value which is an inner presentation and cannot be printed this way.
I really think you should try using a different framework for JSON.