# Module type Container_intf.Container.S1_permissions

    module type S1_permissions = Container_intf.S1_permissions

    type ('a, -'permissions) t

    val mem : ?equal:('a -> 'a -> bool) ->
           ('a, [> Perms.Export.read ]) t -> 'a -> bool

Checks whether the provided element is there, using polymorphic compare if `equal` is not provided

    val length : ('a, [> Perms.Export.read ]) t -> int

    val is_empty : ('a, [> Perms.Export.read ]) t -> bool

    val iter : ('a, [> Perms.Export.read ]) t ->
           f:('a -> unit) -> unit

    val fold : ('a, [> Perms.Export.read ]) t ->
           init:'accum -> f:('accum -> 'a -> 'accum) -> 'accum

`fold t ~init ~f` returns `f (... f (f (f init e1) e2) e3 ...) en`, where `e1..en` are the elements of `t`

    val exists : ('a, [> Perms.Export.read ]) t ->
           f:('a -> bool) -> bool

Returns `true` if and only if there exists an element for which the provided function evaluates to `true`. This is a short-circuiting operation.

    val for_all : ('a, [> Perms.Export.read ]) t ->
           f:('a -> bool) -> bool

Returns `true` if and only if the provided function evaluates to `true` for all elements. This is a short-circuiting operation.

    val count : ('a, [> Perms.Export.read ]) t ->
           f:('a -> bool) -> int

Returns the number of elements for which the provided function evaluates to true.

    val sum : (module Commutative_group.S with type t = 'sum) ->
           ('a, [> Perms.Export.read ]) t ->
           f:('a -> 'sum) -> 'sum

Returns the sum of `f i` for i in the container

    val find : ('a, [> Perms.Export.read ]) t ->
           f:('a -> bool) -> 'a option

Returns as an `option` the first element for which `f` evaluates to true.

    val find_map : ('a, [> Perms.Export.read ]) t ->
           f:('a -> 'b option) -> 'b option

Returns the first evaluation of `f` that returns `Some`, and returns `None` if there is no such element.

    val to_list : ('a, [> Perms.Export.read ]) t -> 'a list

    val to_array : ('a, [> Perms.Export.read ]) t -> 'a array

    val min_elt : ('a, [> Perms.Export.read ]) t ->
           cmp:('a -> 'a -> int) -> 'a option

Returns a min (resp max) element from the collection using the provided `cmp` function. In case of a tie, the first element encountered while traversing the collection is returned. The implementation uses `fold` so it has the same complexity as `fold`. Returns `None` iff the collection is empty.

    val max_elt : ('a, [> Perms.Export.read ]) t ->
           cmp:('a -> 'a -> int) -> 'a option