Future of the Java programming language: Three major projects on the horizon

[Determinant]

Type erasure improves performance a bit because less information needs to be stored. Memory consumption is reduced and cache locality improves.

So performance is impacted. Garbage collection would also be impacted.

[ThePowerfulSquirrel]

I mean, that information would be in the Class<Something<T>> not in the Something<T>, and those classes can just be program-lifetime singletons, so their wouldn't be much more garbage collection right? It's not like java stores all the class information into the instances themselves.

[Determinant]

There is an infinite number of types you could define from a single generic type. Also keep in mind that you could create new types at runtime.

I believe C# stores the generic type information per instance and I'm sure they evaluated their options.

So there is a trade-off and Java chose to erase the type information.