Last Updated: June 6, 2026
Generics give compile-time type safety without runtime overhead, but that bargain comes with a list of things the language won't allow. Most of those restrictions trace back to a single fact: type information is erased before the bytecode runs, so anything that needs T to still exist at runtime is off the table. This lesson walks through the eight common restrictions, why each one exists, and the workaround that gets the job done.