module type S0_phantom_noclass =sig..end
type elt
type 'a container
val length : 'a container -> intval is_empty : 'a container -> boolval iter : 'a container ->
f:(elt -> unit) -> unitval fold : 'a container ->
init:'b -> f:('b -> elt -> 'b) -> 'bval exists : 'a container ->
f:(elt -> bool) -> boolval for_all : 'a container ->
f:(elt -> bool) -> boolval find : 'a container ->
f:(elt -> bool) ->
elt optionval to_list : 'a container ->
elt listval to_array : 'a container ->
elt array