a87a0d089e
Relevant commit messages from squashed history in order: Add initial version of ThinBox update test to actually capture failure swap to middle ptr impl based on matthieu-m's design Fix stack overflow in debug impl The previous version would take a `&ThinBox<T>` and deref it once, which resulted in a no-op and the same type, which it would then print causing an endless recursion. I've switched to calling `deref` by name to let method resolution handle deref the correct number of times. I've also updated the Drop impl for good measure since it seemed like it could be falling prey to the same bug, and I'll be adding some tests to verify that the drop is happening correctly. add test to verify drop is behaving add doc examples and remove unnecessary Pointee bounds ThinBox: use NonNull ThinBox: tests for size Apply suggestions from code review Co-authored-by: Alphyr <47725341+a1phyr@users.noreply.github.com> use handle_alloc_error and fix drop signature update niche and size tests add cfg for allocating APIs check null before calculating offset add test for zst and trial usage prevent optimizer induced ub in drop and cleanup metadata gathering account for arbitrary size and alignment metadata Thank you nika and thomcc! Update library/alloc/src/boxed/thin.rs Co-authored-by: Josh Triplett <josh@joshtriplett.org> Update library/alloc/src/boxed/thin.rs Co-authored-by: Josh Triplett <josh@joshtriplett.org>
27 lines
575 B
Rust
27 lines
575 B
Rust
use alloc::boxed::ThinBox;
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use core::mem::size_of;
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#[test]
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fn want_niche_optimization() {
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fn uses_niche<T: ?Sized>() -> bool {
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size_of::<*const ()>() == size_of::<Option<ThinBox<T>>>()
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}
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trait Tr {}
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assert!(uses_niche::<dyn Tr>());
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assert!(uses_niche::<[i32]>());
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assert!(uses_niche::<i32>());
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}
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#[test]
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fn want_thin() {
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fn is_thin<T: ?Sized>() -> bool {
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size_of::<*const ()>() == size_of::<ThinBox<T>>()
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}
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trait Tr {}
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assert!(is_thin::<dyn Tr>());
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assert!(is_thin::<[i32]>());
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assert!(is_thin::<i32>());
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}
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