From 75cadc09f24bed287d44462ea62f7aa3e4909e77 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Mon, 21 Oct 2024 16:25:06 +0100 Subject: [PATCH] update ABI compatibility docs for new option-like rules --- library/core/src/primitive_docs.rs | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/library/core/src/primitive_docs.rs b/library/core/src/primitive_docs.rs index 22fd47b05962b..95fa6c9c9507c 100644 --- a/library/core/src/primitive_docs.rs +++ b/library/core/src/primitive_docs.rs @@ -1784,9 +1784,11 @@ mod prim_ref {} /// unique field that doesn't have size 0 and alignment 1 (if there is such a field). /// - `i32` is ABI-compatible with `NonZero`, and similar for all other integer types. /// - If `T` is guaranteed to be subject to the [null pointer -/// optimization](option/index.html#representation), then `T` and `Option` are ABI-compatible. -/// Furthermore, if `U` satisfies the requirements [outlined here](result/index.html#representation), -/// then `T` and `Result` and `Result` are all ABI-compatible. +/// optimization](option/index.html#representation), and `E` is an enum satisfying the following +/// requirements, then `T` and `E` are ABI-compatible. Such an enum `E` is called "option-like". +/// - The enum `E` has exactly two variants. +/// - One variant has exactly one field, of type `T`. +/// - All fields of the other variant are zero-sized with 1-byte alignment. /// /// Furthermore, ABI compatibility satisfies the following general properties: ///