module type S1_noclass =sig..end
type 'a container
val length : 'a container -> intval is_empty : 'a container -> boolval iter : 'a container -> f:('a -> unit) -> unitval fold : 'a container -> init:'b -> f:('b -> 'a -> 'b) -> 'bval exists : 'a container -> f:('a -> bool) -> boolval for_all : 'a container -> f:('a -> bool) -> boolval find : 'a container -> f:('a -> bool) -> 'a optionval to_list : 'a container -> 'a listval to_array : 'a container -> 'a array