diff options
Diffstat (limited to 'src/tools/clippy/tests/ui/uninit.rs')
-rw-r--r-- | src/tools/clippy/tests/ui/uninit.rs | 39 |
1 files changed, 33 insertions, 6 deletions
diff --git a/src/tools/clippy/tests/ui/uninit.rs b/src/tools/clippy/tests/ui/uninit.rs index 211317317..c996de894 100644 --- a/src/tools/clippy/tests/ui/uninit.rs +++ b/src/tools/clippy/tests/ui/uninit.rs @@ -1,15 +1,17 @@ #![feature(stmt_expr_attributes)] #![allow(clippy::let_unit_value, invalid_value)] -use std::mem::{self, MaybeUninit}; +use std::mem::MaybeUninit; + +union MyOwnMaybeUninit { + value: u8, + uninit: (), +} fn main() { let _: usize = unsafe { MaybeUninit::uninit().assume_init() }; - // edge case: For now we lint on empty arrays - let _: [u8; 0] = unsafe { MaybeUninit::uninit().assume_init() }; - - // edge case: For now we accept unit tuples + // This is OK, because ZSTs do not contain data. let _: () = unsafe { MaybeUninit::uninit().assume_init() }; // This is OK, because `MaybeUninit` allows uninitialized data. @@ -21,6 +23,31 @@ fn main() { // This is OK, because all constitutent types are uninit-compatible. let _: (MaybeUninit<usize>, [MaybeUninit<bool>; 2]) = unsafe { MaybeUninit::uninit().assume_init() }; + // This is OK, because our own MaybeUninit is just as fine as the one from core. + let _: MyOwnMaybeUninit = unsafe { MaybeUninit::uninit().assume_init() }; + + // This is OK, because empty arrays don't contain data. + let _: [u8; 0] = unsafe { MaybeUninit::uninit().assume_init() }; + // Was a false negative. - let _: usize = unsafe { mem::MaybeUninit::uninit().assume_init() }; + let _: usize = unsafe { MaybeUninit::uninit().assume_init() }; + + polymorphic::<()>(); + polymorphic_maybe_uninit_array::<10>(); + polymorphic_maybe_uninit::<u8>(); + + fn polymorphic<T>() { + // We are conservative around polymorphic types. + let _: T = unsafe { MaybeUninit::uninit().assume_init() }; + } + + fn polymorphic_maybe_uninit_array<const N: usize>() { + // While the type is polymorphic, MaybeUninit<u8> is not. + let _: [MaybeUninit<u8>; N] = unsafe { MaybeUninit::uninit().assume_init() }; + } + + fn polymorphic_maybe_uninit<T>() { + // The entire type is polymorphic, but it's wrapped in a MaybeUninit. + let _: MaybeUninit<T> = unsafe { MaybeUninit::uninit().assume_init() }; + } } |