filter_map is a shorthand for filter + map in a single call.

#### Before

Originally suggested 7 years ago, it was addressing a common idiom to map over an Enumerable, but only include the elements that match a particular filter

Another common approach is selecting + mapping, which is pretty common, for example in ActiveRecord, when manipulating loaded records:

It’s also possible to achieve something similar with:

#### Enumerable#filter_map

We can now use Enumerable#filter_map in Ruby 2.7 to achieve this:

As you see, filter_map creates a new array after first filtering desired results, and then maps to get expected Array.

This comes in pretty handy for creating mapped arrays in a simpler way.

It also gives us a bit of a speedup from its previous counter-parts

As you can see, this is faster with about 10-20% speedup.