Accepting a partial string for an enumaerated type c++

Question

I have enumerated values for genres of music like: "Rock" "Country" "Techno" etc. We have take an input from a test script and assign it to an enumerated type. I have been able to assign the exact strings to the enumerated type for example if "Rock" was entered it would assign that object to the enumerated type of Rock; however, if Alternative Rock were entered I can not find a way to accept that partial string of Rock and assign it to enumerated type "Rock" with the genre name of "Alternative Rock" I tried using std::find but had no luck. I apologize if this questions is confusing I can elaborate more with code if needed.