m04-zero-cost

Zero-cost abstraction in Rust is achieved by deciding between compile-time generics and runtime trait objects to preserve performance while maintaining API expressiveness.

Choosing between static dispatch and dynamic dispatch involves analyzing monomorphization costs versus dynamic dispatch overhead for your specific performance-sensitive code paths.

Use trait objects instead of generics when dynamic dispatch overhead is acceptable and you need runtime polymorphism rather than compile-time monomorphization guarantees.

Rust generics increase compile times due to monomorphization generating specialized code for each type, which trades compile overhead for zero-cost runtime performance.

Dynamic dispatch impacts performance because trait objects use a vtable pointer lookup at runtime instead of static dispatch, adding indirect call overhead to execution paths.

Document design decisions by validating compile-time guarantees for static dispatch and recording the trade-offs accepted when selecting dynamic trait objects for your library APIs.