m04▌

Layer 1: Language Mechanics

Compile-time versus runtime polymorphism: generics, trait objects, and zero-cost abstraction patterns. \n \n Distinguishes static dispatch (generics, impl Trait ) from dynamic dispatch ( dyn Trait ), with decision guidance on when each is appropriate based on type knowledge, performance priorities, and collection heterogeneity \n Maps common type system errors (E0277, E0308, E0599, E0038) to underlying design questions rather than mechanical fixes \n Covers object safety constraints, monomorphiz