What is this "type erasure" thing you speak of? It's not something at the other end of a pencil (remember those?) but a way to hold an object without knowing its exact type. Andrzej explains:

Type Erasure, Part 1

by Andrzej Krzemieński

From the article:

Have you ever came across term type erasure in C++? This “pattern” or “technique” is growing more and more popular. In this post I will try to describe what it is. Note that it is something different than a similar term in Java.

What does type encode?

Let’s start with describing the opposite of type erasure. We could call such situation “type-full-ness”. Forget the term though, let me illustrate what I mean with an example. ...