API and Interface Design

Overview

The headline rule, from Scott Meyers (97/55), governs everything else: make interfaces easy to use correctly and hard to use incorrectly. Every other decision below is a tactic for that rule — encapsulate behavior so callers can't reach past the contract, lean on the type system so wrong calls fail at compile time.

This is a rigid skill. Run the decisions in order. If you can't satisfy one, stop and tell the user what's blocking you.

When to invoke

Invoke when you're about to: