Input functions
Since closures may be used as arguments, you might wonder if the same can be said about functions. And indeed they can! If you declare a function that takes a closure as parameter, then any function that satisfies the trait bound of that closure can be passed as a parameter.
As an additional note, the Fn
, FnMut
, and FnOnce
traits
dictate how
a closure captures variables from the enclosing scope.