Fix pointer value in the 'complex example' on stack/heap #30115
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The `f` argument will reference the actual value in the `d` box, not the box in the `bar`'s stack frame.
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@bors: r+ rollup |
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📌 Commit 7728742 has been approved by |
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⌛ Testing commit 7728742 with merge 937efb3... |
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Thank you! I agree that this could use some simplification. |
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Oh, and for why: https://users.rust-lang.org/t/im-having-trouble-following-an-example-in-the-stack-and-the-heap/3666/6 <- we found this bug recently, but I hadn't had the time to update the example. |
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💔 Test failed - auto-mac-64-nopt-t |
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Great explanation in the linked thread, thanks! |
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@bors: retry |
…teveklabnik
The `f` argument will reference the actual value in the `d` box, not the box in the `bar`'s stack frame.
I am just learning Rust, so I don't know how to explain this well, but just from `f`'s type it is clear that it will be a pointer to an `i32`, not a pointer to a pointer. Some `println!("{:p}", ...)`'s can easily confirm this.
I would actually suggest to remove/simplify this part of the example. This is a subtle issue that can easily confuse people at the early stages of familiarizing with the language. (As I got confused by it. :))
The
fargument will reference the actual value in thedbox, not the box in thebar's stack frame.I am just learning Rust, so I don't know how to explain this well, but just from
f's type it is clear that it will be a pointer to ani32, not a pointer to a pointer. Someprintln!("{:p}", ...)'s can easily confirm this.I would actually suggest to remove/simplify this part of the example. This is a subtle issue that can easily confuse people at the early stages of familiarizing with the language. (As I got confused by it. :))