[bluGill]

What does inferior mean?

Rust is inferior to C++ for my needs. This is just a reflection on we started a large project in C++ before rust existed, and now have millions of lines. Getting Rust to work with our existing C++ is hard enough as to not be worth it. Rewriting in Rust would cost 1 billion dollars. Thus despite all the problems we have with C++ that Rust would solve, rust is inferior.

(Rust is working on their C++ interoperability story and we are making changes that will allow using Rust in the future so I reserve the right to change this story in a few years, but only time will tell)

[simonask]

I don't think it's a defect of the language that your particular circumstance makes it infeasible to port your project. Having a great C++ interop story would be amazing, but Rust would be decidedly less awesome if it had made concessions in that direction early on.

There's a lot of warts here, particularly around the fact that all Rust types are "trivially relocatable" in C++ parlance. At the same time, figuring out which C++ types are trivially relocatable is pretty difficult. To give you an idea of the current situation, all or most non-POD C++ types must be "pinned" on the Rust side, forcing you to deal with the rather clunky `Pin<&mut T>` API. Either that or heap-allocating all C++ types owned from Rust code. Not great.

The story is likely to improve, hopefully. There's an interesting overview here: https://hackmd.io/@rust-lang-team/rJvv36hq1e

[bluGill]

I didn't say it was a defect. I said it made rust inferior for me. Those are different things. I don't disagree with rust reasons for making that tradeoff - but the tradeoff as a result makes rust useless for now, for me. If it works for you great.

[simonask]

I think the term "inferior" isn't really appropriate, then. It typically applies to the quality of the thing on its own, not its applicability outside of its stated scope.