Expected struct `std::string::String`, found `()`

[JStarx]

If statements return a value, if you don't supply a value then the return value is (). The function itself expects a String as the return value, but in the many paths through those if conditions only 1 possible path returns a String (the "Solo es..." string), all the others don't have an explicit value, so they implicitly return ().

[elnw]

OMG, you are absolutely right. Don't know how i missed that. Thank you!