what about generics (equivalent to templates in C++), which allow compile time optimizations all the way down which may not possible if the implementation is hidden behind a void*?
Unless you use `dyn`, all code is monomorphized, and that code on its own will get optimized.
This does come with code-bloat. So the Rust std sometimes exposes a generic function (which gets monomorphized), but internally passes it off to a non-generic function.
This to avoid that the underlying code gets monomorphized.
> This does come with code-bloat. So the Rust std sometimes exposes a generic function (which gets monomorphized), but internally passes it off to a non-generic function.
There's no free lunch here. Reducing the amount of code that's monomorphised reduces the code emitted & improves compile times, but it reduces the scope of the code that's exposed to the input type, which reduces optimisation opportunities.
In C, the only way to write a monomorphized hash table or array list involves horribly ugly macros that are difficult to write and debug. Rust does monomorphization by default, but you can also use &dyn trait for vtable-like behaviour if you prefer.
