20.5 Disadvantages of Trait Objects
While trait objects are powerful and can emulate certain OOP use cases, they come with drawbacks:
- Performance Costs: Function calls on trait objects cannot be inlined and must go through a vtable, incurring runtime overhead.
- Fewer Compile-Time Optimizations: Statically dispatched generics benefit from monomorphization (the compiler generates specialized code per type), which is not possible with dynamic dispatch.
- Limited Data Access: Trait objects focus on behavior, so data access often requires additional methods or downcasting.
For projects where performance is crucial and type sets are known in advance, static dispatch through generics is often preferred over trait objects.