Thread: Generics

Type erasure isn't something you use, it's what the compiler does. The generics syntax is a compile-time way for the compiler to check that you're using the correct types. All (most of) that type information is removed during compilation so the compiled code doesn't have it and the Java runtime can't use it. Hence 'type erasure'. See Type Erasure.

For technical reasons, the runtime needs some type information for anonymous classes, so some type information is retained when anonymous classes are compiled. This is accessible (through messy tricks like those in the article), but it really seems like cutting off your nose to spite your face - making the syntax a tiny bit simpler or avoiding a minor inconvenience by sacrificing simplicity, robustness and performance... YMMV.

I know what type erasure is. But I confess I got kind of confused by the article. Thought that if you could avoid making casts then it could improve performance, or something. Now that I think of it I realize it would just become a mess.