The <numeric> header – accumulate

It's interesting to see that the two higher-order functions that form the map/reduce pattern, one of the most commonly known patterns in functional programming, ended up in two different header files in C++. The transform/accumulate combination, requiring both the <algorithm> and the <numeric> header files, allow us to solve many problems that have the following pattern:

• A collection is provided.
• The collection needs to be transformed into something else.
• An aggregated result needs to be computed.

Let's look at a few examples.

Computing the total price with tax for a shopping cart

Let's say we have a Product structure, as follows:

struct Product{
 ...