zeroize: support unsized types in Zeroizing#1318
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This commit adds ?Sized to the generic bounds on Zeroizing and many of its trait implementations. This makes it possible to form and use types like `Zeroizing<Box<[u8]>>` and `Zeroizing<Arc<[u8]>>`.
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ssanderson
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Dec 30, 2025
| // This is a weird way to use zeroizing, but it's technically allowed b/c | ||
| // unsized types can be stored inside Zeroizing, so make sure it works as | ||
| // expected. | ||
| #[test] |
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I think this is missing a feature = "alloc" guard since it uses Box, but it seems like the build is still passing. Are these guards actually required?
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Since these tests are in tests/ they're in their own toplevel crate which links alloc and std by default.
You only need to gate alloc if it's using alloc-dependent functionality inside Zeroize. Since this is Box<Zeroizing<[u8]>> and not Zeroizing<Box<[u8]>> (which would need the Zeroize impl on Box) you're not actually dependent on zeroize having its alloc feature enabled.
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Going to go ahead and merge this. I might revisit the feature-gating myself. |
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Jun 12, 2026
## Added - `Zeroizing` is now `repr(transparent)` ([#1253]) - `optimization_barrier` function ([#1261]) - `Zeroizing` now supports `?Sized` ([#1318]) - `zeroize_stack` function ([#1331]) ## Changed - Edition changed to 2024 and MSRV bumped to 1.85 ([#1149]) - Replace `atomic_fence` with `optimization_barrier` ([#1252]) - Bump `zeroize_derive` to v1.5 ([#1492]) - Always enable AVX-512 support ([#1493]) [#1149]: #1149 [#1252]: #1252 [#1253]: #1253 [#1261]: #1261 [#1318]: #1318 [#1331]: #1331 [#1492]: #1492 [#1493]: #1493
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This commit adds
?Sizedto the generic bounds on Zeroizing and many of its trait implementations. This makes it possible to form and use types likeZeroizing<Box<[u8]>>andZeroizing<Arc<[u8]>>.This also allows forming more exotic types like
Zeroizing<dyn SomeTrait>whereSomeTrait: Zeroize. I've included a test for that case to ensure that nothing unexpected breaks if it's used in that way, but that usage is probably not to be recommended.See #1256 for more details.