Step 5 of 6
string search and substrings
Handy std::string members:
std::string s = "de_dust2";
s.find("dust"); // 3 (index of first match)
s.find("zz"); // std::string::npos (not found)
s.substr(3, 4); // "dust" (start, length)
s.substr(3); // "dust2" (to the end)
Your turn: write std::string map_name(const std::string& s) that strips a prefix ending in the first _. "de_dust2" becomes "dust2"; a string without _ is returned unchanged.