Ds\Deque::apply

Updates all values by applying a callback function to each value

&reftitle.description; public `void` `Ds\Deque::apply` `callable` `callback`

Updates all values by applying a `callback` function to each value in the deque.

&reftitle.parameters;

`callback`

- `mixed` ``callback`` `mixed` `value`

  A `callable` to apply to each value in the deque.

  The callback should return what the value should be replaced by.

&reftitle.returnvalues;

&return.void;

&reftitle.examples;

### `Ds\Deque::apply` example

    <?php
    $deque = new \Ds\Deque([1, 2, 3]);
    $deque->apply(function($value) { return $value * 2; });

    print_r($deque);
    ?>

&example.outputs.similar;

    Ds\Deque Object
    (
        [0] => 2
        [1] => 4
        [2] => 6
    )