Backward Compatibility in Rust

Hi, I really love rust and I will like it to be my primary programming language. I'm confused, with many crates out there, will rust still be backward compatible ? I love Java for it backwards compatibility.

The backward compatibility guarantees of Rust (the language itself) don't depend on external crates. What particular problem/scenario do you have in mind that would imply otherwise?


If a crate compiled at some point, then Rust's stability guarantees say that it'll still compile afterwards.

Now there's no guarantee that you can swap out version 1.x.x of a user provided crate with version 2.y.y and that your program still works, since that's not semver compatible.

But if a crate was written in edition e (which was released for rust version v_e) and written in rust version w, then all versions k >= w and k >= v_e, of rust will compile the crate (as long as no unstable features are used). This is ignoring the use of deprecated features, where you really should just update/patch your library, however you will get a grace period where it's a warning.


Rust has a tool called crater that compiles and tests every crate. It's used to verify that new versions of Rust are compatible with all crates.


Thanks, it being answered

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It's worth noting that backwards compatibility it's the same thing as having language breaking changes introduced.

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