Calls @func for each element in the queue passing @user_data to the function.
It is safe for @func to remove the element from @queue, but it must not modify any part of the queue after that element.
the function to call for each element's data
user data to pass to @func
2.4
See Implementation
Calls @func for each element in the queue passing @user_data to the function.
It is safe for @func to remove the element from @queue, but it must not modify any part of the queue after that element.