20 lines
996 B
Markdown
20 lines
996 B
Markdown
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# maybe-uninit
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Quite often, uses of `std::mem::uninitialized()` end up in unsound code.
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Therefore, the `MaybeUninit` union has been added to `std::mem` and `std::mem::uninitialized()` is being deprecated.
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However, `MaybeUninit` has been added quite recently.
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Sometimes you might want to support older versions of Rust as well.
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Here is where `maybe-uninit` comes in: it supports stable Rust versions starting with 1.20.0.
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Sadly, a feature-complete implementation of `MaybeUninit` is not possible on stable Rust.
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Therefore, the library offers the guarantees of `MaybeUninit` in a staged fashion:
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* Rust 1.36.0 onward: `MaybeUninit` implementation of Rust stable is being re-exported
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* Rust 1.22.x - 1.35.0: No panicing on uninhabited types,
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unsoundness when used with types like `bool` or enums.
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However, there is protection from accidentially `Drop`ing e.g. during unwind!
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* Rust 1.20.x - 1.21.x: No support for Copy/Clone of `MaybeUninit<T>`,
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even if `T` impls `Copy` or even `Clone`.
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