diff options
| -rw-r--r-- | library/core/src/mem/mod.rs | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/library/core/src/mem/mod.rs b/library/core/src/mem/mod.rs index 9054ade2d79..dd4b6e82343 100644 --- a/library/core/src/mem/mod.rs +++ b/library/core/src/mem/mod.rs @@ -1266,6 +1266,20 @@ impl<T> SizedTypeProperties for T {} /// // ^^^ error[E0616]: field `private` of struct `Struct` is private /// ``` /// +/// Only [`Sized`] fields are supported, but the container may be unsized: +/// ``` +/// # use core::mem; +/// #[repr(C)] +/// pub struct Struct { +/// a: u8, +/// b: [u8], +/// } +/// +/// assert_eq!(mem::offset_of!(Struct, a), 0); // OK +/// // assert_eq!(mem::offset_of!(Struct, b), 1); +/// // ^^^ error[E0277]: doesn't have a size known at compile-time +/// ``` +/// /// Note that type layout is, in general, [subject to change and /// platform-specific](https://doc.rust-lang.org/reference/type-layout.html). If /// layout stability is required, consider using an [explicit `repr` attribute]. |