Checks whether the provided element is there, using polymorphic compare if equal
is not provided
fold t ~init ~f returns f (... f (f (f init e1) e2) e3 ...) en, where e1..en
are the elements of t
Returns true if and only if there exists an element for which the provided
function evaluates to true. This is a short-circuiting operation.
Returns true if and only if the provided function evaluates to true for all
elements. This is a short-circuiting operation.
Returns the number of elements for which the provided function evaluates to true.
Returns as an option the first element for which f evaluates to true.
Returns the first evaluation of f that returns Some, and returns None if there
is no such element.
Returns a minimum (resp maximum) element from the collection using the provided
cmp function, or None if the collection is empty. 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.
create () returns an empty bag.
remove_one t removes some element from the bag, and returns its value.
remove_one runs in constant time.
clear t removes all elements from the bag. clear runs in O(1) time.
filter_inplace t ~f removes all the elements from t that don't satisfy f.
until_empty t f repeatedly removes a value v from t and runs f v,
continuing until t is empty. Running f may add elements to t if it
wants.
unchecked_iter t ~f behaves like iter t ~f except that f is allowed to modify
t. Elements added by f may or may not be visited, elements removed by f that
have not been visited will not be visited. It is an (undetected) error to delete the
current element.