20.5 Disadvantages of Trait Objects
While trait objects enable dynamic polymorphism, they have trade-offs:
- Performance Costs: Calls cannot be inlined easily and must go through a vtable, incurring runtime overhead.
- Fewer Compile-Time Optimizations: Generics benefit from specialization (monomorphization), which dynamic dispatch cannot provide.
- Limited Data Access: Trait objects emphasize behavior over data. Accessing fields of the underlying struct usually involves more explicit methods or downcasting.
For performance-critical applications or scenarios where all concrete types are known in advance, static dispatch with generics is often preferred.