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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:03:36 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:03:36 +0000 |
commit | 17d40c6057c88f4c432b0d7bac88e1b84cb7e67f (patch) | |
tree | 3f66c4a5918660bb8a758ab6cda5ff8ee4f6cdcd /src/tools/clippy/src/docs/uninit_assumed_init.txt | |
parent | Adding upstream version 1.64.0+dfsg1. (diff) | |
download | rustc-upstream/1.65.0+dfsg1.tar.xz rustc-upstream/1.65.0+dfsg1.zip |
Adding upstream version 1.65.0+dfsg1.upstream/1.65.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/tools/clippy/src/docs/uninit_assumed_init.txt')
-rw-r--r-- | src/tools/clippy/src/docs/uninit_assumed_init.txt | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/tools/clippy/src/docs/uninit_assumed_init.txt b/src/tools/clippy/src/docs/uninit_assumed_init.txt new file mode 100644 index 000000000..cca24093d --- /dev/null +++ b/src/tools/clippy/src/docs/uninit_assumed_init.txt @@ -0,0 +1,28 @@ +### What it does +Checks for `MaybeUninit::uninit().assume_init()`. + +### Why is this bad? +For most types, this is undefined behavior. + +### Known problems +For now, we accept empty tuples and tuples / arrays +of `MaybeUninit`. There may be other types that allow uninitialized +data, but those are not yet rigorously defined. + +### Example +``` +// Beware the UB +use std::mem::MaybeUninit; + +let _: usize = unsafe { MaybeUninit::uninit().assume_init() }; +``` + +Note that the following is OK: + +``` +use std::mem::MaybeUninit; + +let _: [MaybeUninit<bool>; 5] = unsafe { + MaybeUninit::uninit().assume_init() +}; +```
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