Re:Abstraction without overhead: traits in Rust
by haberman on Tuesday May 12, 2015 @05:43PM
(#9535141)
> That's assuming that a "full pointer" (i.e. an unpredictable address to an arbitrary point in heap memory) is the only way to get a reference to an object.
No, it's assuming that a "full pointer" is the only way to get a reference to a polymorphic object. This is true in both C++ and Rust.
> What about if you want to stick a bunch of objects in a vector, and iterate over them linearly?
You can do this in both C++ and Rust. But you can only put a bunch of objects in a vector if they have a statically-known type. The point of dynamic dispatch is calling methods of an object where you don't statically know its type.
No, it's assuming that a "full pointer" is the only way to get a reference to a polymorphic object. This is true in both C++ and Rust.
> What about if you want to stick a bunch of objects in a vector, and iterate over them linearly?
You can do this in both C++ and Rust. But you can only put a bunch of objects in a vector if they have a statically-known type. The point of dynamic dispatch is calling methods of an object where you don't statically know its type.