Overloading on return type for map access

#include <iostream>
#include <string>
#include <map>

struct Properties {
    Properties();
    Properties(std::string key) : key_(key) {};
    std::map<std::string, std::string> props = { {"string", "string"}, {"int", "46"}, {"bool", "false"} };
    operator std::string() { return getString(); };
    operator bool() { return getBool(); };
    operator int() { return getInt(); };
private:
    std::string key_;
    int getInt() { if (props[key_].find_first_of("0123456789") != std::string::npos) return std::stoi(props[key_]); };
    bool getBool() { if (props[key_].find("true") != std::string::npos || props[key_].find("false") != std::string::npos) return (props[key_].find("true") != std::string::npos); };
    std::string getString() { return props[key_]; };
};


int main() {
    int integer = Properties("int");
    std::string text = Properties("string");
    bool boolean = Properties("bool");
    std::cout << "int, string, bool: " << integer << ' ' << text << ' ' << boolean << '\n';
    return 0;
}