From a63d414031dc0cb4af3e3e8066a7a04ab8436bcd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Mi=C4=85sko?= <tomasz.miasko@gmail.com>
Date: Tue, 3 May 2022 00:00:00 +0000
Subject: [PATCH] Update `ProjectionElem::Downcast` documentation
`ProjectionElem:::Downcast` is used when downcasting to a variant of
an enum or a generator, regardless of the number of variants.
---
compiler/rustc_middle/src/mir/mod.rs | 4 +---
compiler/rustc_middle/src/mir/tcx.rs | 2 +-
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 188ca8048055c..924bacb7aae21 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -2017,9 +2017,7 @@ pub enum ProjectionElem<V, T> {
from_end: bool,
},
- /// "Downcast" to a variant of an ADT. Currently, we only introduce
- /// this for ADTs with more than one variant. It may be better to
- /// just introduce it always, or always for enums.
+ /// "Downcast" to a variant of an enum or a generator.
///
/// The included Symbol is the name of the variant, used for printing MIR.
Downcast(Option<Symbol>, VariantIdx),
diff --git a/compiler/rustc_middle/src/mir/tcx.rs b/compiler/rustc_middle/src/mir/tcx.rs
index 597ade4223684..f1d5201454d69 100644
--- a/compiler/rustc_middle/src/mir/tcx.rs
+++ b/compiler/rustc_middle/src/mir/tcx.rs
@@ -12,7 +12,7 @@ use rustc_target::abi::VariantIdx;
#[derive(Copy, Clone, Debug, TypeFoldable)]
pub struct PlaceTy<'tcx> {
pub ty: Ty<'tcx>,
- /// Downcast to a particular variant of an enum, if included.
+ /// Downcast to a particular variant of an enum or a generator, if included.
pub variant_index: Option<VariantIdx>,
}