A useful member function of the string class is find. The call str$.$find$($ch$)$ returns the position of the first occurrence of ch in str$,$ or the "special" value, string::npos if there is no match. We could have implemented the first$\_$space function as return str$.$find$("").$ However, that function is not useful if we have alternatives, such as "any vowel".

Implement a function that uses the find member function and finds the first position of any characters from a set in a given string. For example, first$\_$in$\_$set$("$spring$",$ "aeiou"$)$ returns $3$ because $"$i$"$ occurs in the set "aeiou" and the preceding characters do not.

If there is no match, then return $-1.$

Use multiple return statements. As soon as you have computed the answer, return it$.$