A ToDo list using multimap

An ordered task list (or a ToDo list) is a common computing application. Formally stated, it's a list of tasks associated with a priority, sorted in reverse numerical order.

You may be tempted to use a priority_queue for this, because as the name implies, it's already sorted in priority (reverse numerical) order. The disadvantage of a priority_queue is that it has no iterators, so it's difficult to operate on it without pushing and popping items to and from the queue.

For this recipe, we'll use a multimap for the ordered list. The multimap associative container keeps items in order, and it can be accessed using reverse iterators for the proper sort order.

How to do it…

This is a short and simple recipe that initializes a multimap and prints it in reverse order.

• We start with a type alias for our multimap:

  using todomap = multimap<int, string>;

Our todomap is a multimap with an int key and a string...