Integer(), Float() and Rational() errs at successive underscores, and String#to_i stops the conversion there.
But String#to_f and String#to_r continue the conversion like as there were just one underscore.
Is this intentional?
Subject changed from `String#to_f` and `String#to_r` don't stop successive underscores to `String#to_f` and `String#to_r` don't stop at successive underscores