[Verdex]

I'm glad you commented because this is what I wanted to say, but couldn't think of a good way to lead into it.

IIRC while Rust does allow you to switch up allocators, it doesn't let you mix and match your runtime with multiple allocators. (Each artifact can be linked with at most one allocator at a time.) There are applications where you want to have multiple allocation strategies for performance reasons.

Uniqueness is really useful for most applications, but there are times that you want data structures that allow multiple pointers to the same data. Having to do this in Rust is going to be a bigger chore than doing it in a language that doesn't support uniqueness.

It will be possible for Rust to still participate in these areas (especially because you can use Rust for only part of your project, so you can use it where you don't have allocation or nonuniqueness constraints in your problem space). However, other options are going to offer a better programmer experience.

[steveklabnik]

> IIRC while Rust does allow you to switch up allocators, it doesn't let you mix and match your runtime with multiple allocators. (Each artifact can be linked with at most one allocator at a time.) There are applications where you want to have multiple allocation strategies for performance reasons.

So, sort of yes, and sort of no. Like, you can swap the global allocator, but there's no way to parameterize standard library stuff over anything but the given allocator. But for your own code, you can write and use allocators however you want. Arenas are often popular, for example.