Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

zero-sized type

A type whose values take 0 bytes, like a unit struct.

A zero-sized type has size_of 0 (for example struct Marker;); it exists for the type checker only.

Loading interactive…

Examples

struct Draft; has size_of::<Draft>() equal to 0, and so does ().