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Some Result combinations work like an Option.

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Lokathor 2024-05-07 18:08:36 -06:00
parent d71b3f486a
commit f94fa6bee3
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library/core/src/result.rs
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@ -224,6 +224,21 @@
//! [`Err(E)`]: Err
//! [io::Error]: ../../std/io/struct.Error.html "io::Error"
//!
//! # Representation
//!
//! In some cases, [`Result<T, E>`] will gain the same size, alignment, and ABI
//! guarantees as [`Option<T>`] has. One of either the `T` or `E` type must be a
//! type that qualifies for `Option` guarantees, and the *other* type must meet
//! all of the following conditions:
//! * Is a zero-sized type with alignment 1 (a "1-ZST").
//! * Has no fields.
//! * Does not have the #[non_exhaustive] attribute.
//!
//! For example, `Result<NonZeroI32, ()>` or `Result<(), NonZeroI32>` would both
//! have the same guarantees as `Option<NonZeroI32>`. The only difference is the
//! implied semantics: `Result<NonZeroI32, ()>` is "a non-zero success value"
//! while `Result<(), NonZeroI32>` is "a non-zero error value".
//!
//! # Method overview
//!
//! In addition to working with pattern matching, [`Result`] provides a