ptree get_value with name including "." - c++

Question

"A": "1"
"A.B": "2"
"A.C": "3"
How to get the value of A.B if i iterate through the ptree it works. if i try
to get value of pt.get_child("A\.B").get_value<std::string>(). i get the following exception
terminate called after throwing an instance of boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::property_tree::ptree_bad_path> >'
what(): No such node
please find the complete code below
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/ini_parser.hpp>
#include <iostream>
#include <string>
#include <iterator>
using boost::property_tree::ptree;
/* Indent Json Output */
std::string indent(int level) {
std::string s;
for (int i = 0; i < level; i++) s += " ";
return s;
}
/* Print tree in json format */
void printTree(ptree & pt, int level) {
if (pt.empty()) {
std::cerr << "\"" << pt.data() << "\"";
} else {
if (level) std::cerr << std::endl;
std::cerr << indent(level) << "{" << std::endl;
for (ptree::iterator pos = pt.begin(); pos != pt.end();) {
std::cerr << indent(level + 1) << "\"" << pos-> first << "\": ";
printTree(pos->second, level + 1);
++pos;
if (pos != pt.end()) {
std::cerr << ",";
}
std::cerr << std::endl;
}
std::cerr << indent(level) << " }";
}
return;
}
int main()
{
ptree pt;
read_ini("sample.ini", pt);
printTree(pt, 0);
std::cout << pt.get_child("A.B").get_value<std::string>() << std::endl; //tries to resolve A.B to two nodes
std::cout << pt.get_child("A\\.B").get_value<std::string>() << std::endl; //error
}
sample.ini
A=1
A.B=2
A.C=3

Answer 1

You can use alternative path delimiters, but it's a bit tricky and not very well documented.
You have to temporarily specify an alternative path separator:
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#include <boost/property_tree/ini_parser.hpp>
#include <iostream>
using boost::property_tree::ptree;
int main() {
ptree pt;
pt.put("a.b", "first");
pt.put(ptree::path_type("a|complicated.name", '|'), "second");
write_ini(std::cout, pt);
}
Prints
[a]
b=first
complicated.name=second