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0 pointskketch7mo ago0 comments

True. But I would not expect any programming language to do that.

Rust provides safeguards and helps you to enforce mutability and ownership at the language level, but how you leverage those safeguards is still up to you.

If you really want it you can still get Rust to mutate stuff when you call a non mutable function after all. Like you could kill someone with a paper straw

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eru7mo ago

> True. But I would not expect any programming language to do that.

Haskell (and its more research-y brethren) do exactly this. You mark your functions with IO to do IO, or nothing for a pure function.

Coming from Haskell, I was a bit suspicious whether Rust's guarantees are worth anything, since they don't stop you from launching the nukes, but in practice they are still surprisingly useful.

Btw, I think D has an option to mark your functions as 'pure'. Pure functions are allowed internal mutation, but not side effects. This is much more useful than C++'s const. (You can tell that D, just like Rust, was designed by people who set out to avoid and improve on C++'s mistakes.)

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