val to_int : [> `Read ] t -> int optionval to_float : [> `Read ] t -> float optionval index : [> `Read ] t -> char -> int optionval rindex : [> `Read ] t -> char -> int optionval index_from : [> `Read ] t -> int -> char -> int optionval rindex_from : [> `Read ] t -> int -> char -> int optionval find : [> `Read ] t -> [> `Read ] t -> int optionval find_from : [> `Read ] t -> int -> [> `Read ] t -> int optionval rfind : [> `Read ] t -> [> `Read ] t -> int optionval rfind_from : [> `Read ] t -> int -> [> `Read ] t -> int optionval split : [> `Read ] t -> by:[> `Read ] t -> (_ t * _ t) optionval rsplit : [> `Read ] t -> by:[> `Read ] t -> (_ t * _ t) option