m04-zero-cost

Choose generics for static dispatch and monomorphization when performance is critical, and trait objects for dynamic dispatch when runtime flexibility is needed. This skill guides the Rust polymorphism decision process by evaluating monomorphization trade-offs, object safety constraints, and API design patterns.

Object safety in Rust determines whether a trait can be used as a trait object for dynamic dispatch. This skill explains object safety rules and common error patterns like E0277 and E0308, showing how methods lacking certain properties prevent trait object creation.

Static dispatch via generics inlines code for performance, while dynamic dispatch via trait objects enables runtime polymorphism. This skill provides practical design considerations for reusable Rust APIs, weighing code reuse, performance, and binary size.

Monomorphization in Rust duplicates code for each generic type instantiation, increasing binary size. This skill explains monomorphization trade-offs and provides guidelines for balancing static dispatch performance against binary size constraints.

Dynamic dispatch via trait objects enables plugin-like architectures in Rust, though it introduces runtime overhead compared to generics. This skill provides design considerations for plugin architectures while maintaining optimal performance where possible.

Common Rust compiler errors when implementing polymorphism include E0277 and E0308, often related to type mismatches or object safety violations. This skill explains these error patterns and provides practical guidelines to resolve them.