Topic 9. Generic programming (generics)

Goal: learn to create type-safe containers and algorithms, choose sufficient parameter bounds, and test their contracts.

Lecture contents

1. Type parameters, classes, and methods — From Object to a type parameter · Generic classes, records, and diamond · Generic methods and type argument inference
2. Bounds and invariance — Bounded type parameters · Invariance and the difference from arrays
3. Wildcards and the PECS principle — Wildcards and the PECS principle · Wildcard capture and helper methods
4. Type erasure and its consequences — Type erasure and generated bridges · Generics restrictions · Example 4. An array-based stack
5. Raw types and standard contracts — Raw types and heap pollution · Generic results and standard contracts

Practice and review

• Practice — 3 worked examples with complete code
• Tasks — 30 variants, each with tasks at three difficulty levels
• Summary — conclusions, self-check questions, and useful links