From 71a4add26e39d9d1f45ab987741a99e465bb0f5e Mon Sep 17 00:00:00 2001 From: Noah Lev Date: Tue, 21 Sep 2021 19:12:10 -0700 Subject: [PATCH] Document `--show-type-layout` in the rustdoc book --- src/doc/rustdoc/src/unstable-features.md | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/doc/rustdoc/src/unstable-features.md b/src/doc/rustdoc/src/unstable-features.md index b55db452f12..d669230b8bf 100644 --- a/src/doc/rustdoc/src/unstable-features.md +++ b/src/doc/rustdoc/src/unstable-features.md @@ -209,6 +209,22 @@ some consideration for their stability, and names that end in a number). Giving `rustdoc` will disable this sorting and instead make it print the items in the order they appear in the source. +### `--show-type-layout`: add a section to each type's docs describing its memory layout + +Using this flag looks like this: + +```bash +$ rustdoc src/lib.rs -Z unstable-options --show-type-layout +``` + +When this flag is passed, rustdoc will add a "Layout" section at the bottom of +each type's docs page that includes a summary of the type's memory layout as +computed by rustc. For example, rustdoc will show the size in bytes that a value +of that type will take in memory. + +Note that most layout information is **completely unstable** and may even differ +between compilations. + ### `--resource-suffix`: modifying the name of CSS/JavaScript in crate docs Using this flag looks like this: