Change how boost::property_tree reads translates strings to bool

Question

I\'ve gotten lost in the header files for the boost property_tree and given the lack of documentation around the lower layers, I\'ve decided to ask what the easy way is to o

Answer 1

There is also a good example at theboostcpplibraries.com.

Based on that, I wrote for a custom parser (declaration omitted):

boost::optional string_to_bool_translator::get_value(const std::string &s) {
    auto tmp = boost::to_lower_copy(s);
    if (tmp == "true" || tmp == "1" || tmp == "y" || tmp == "on") {
       return boost::make_optional(true);
    } else if (tmp == "false" || tmp == "0" || tmp == "n" || tmp == "off") {
      return boost::make_optional(false);
    } else {
        return boost::none;
    }
} 

It's only for bool and std::string but easily extendable.

Then,

boost::property_tree::ptree pt;
...
string_to_bool_translator tr;
auto optional_value = pt.get_optional(key, tr);