From 7b103e7dd2df75e4e8dbb333bc79ffc7e9304f65 Mon Sep 17 00:00:00 2001
From: Jacob Pratt <jacob@jhpratt.dev>
Date: Mon, 22 Nov 2021 20:17:53 -0500
Subject: Use `derive_default_enum` in the compiler

---
 compiler/rustc_middle/src/lib.rs    | 1 +
 compiler/rustc_middle/src/ty/sty.rs | 9 ++-------
 2 files changed, 3 insertions(+), 7 deletions(-)

(limited to 'compiler/rustc_middle')

diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index 0894b805075..9ce9f65a490 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -30,6 +30,7 @@
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(core_intrinsics)]
+#![feature(derive_default_enum)]
 #![feature(discriminant_kind)]
 #![feature(exhaustive_patterns)]
 #![feature(if_let_guard)]
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index c79e25f4781..7e054d1e17f 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -2263,10 +2263,11 @@ impl<'tcx> TyS<'tcx> {
 /// a miscompilation or unsoundness.
 ///
 /// When in doubt, use `VarianceDiagInfo::default()`
-#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
 pub enum VarianceDiagInfo<'tcx> {
     /// No additional information - this is the default.
     /// We will not add any additional information to error messages.
+    #[default]
     None,
     /// We switched our variance because a type occurs inside
     /// the generic argument of a mutable reference or pointer
@@ -2301,9 +2302,3 @@ impl<'tcx> VarianceDiagInfo<'tcx> {
         }
     }
 }
-
-impl<'tcx> Default for VarianceDiagInfo<'tcx> {
-    fn default() -> Self {
-        Self::None
-    }
-}
-- 
cgit 1.4.1-3-g733a5