X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compiler%2Frustc_middle%2Fsrc%2Fty%2Fconsts%2Fkind.rs;h=becc2b805dd1ee9ffb3ca9c50eb6b346e697a996;hb=c89bff29e562540c14497aa8cc8490e6a2cdeb73;hp=de63dae8a3df6455eb311d18c3eef5b717535591;hpb=df04d28163cc42e2c5b1072abe68460f904e42be;p=rust.git

diff --git a/compiler/rustc_middle/src/ty/consts/kind.rs b/compiler/rustc_middle/src/ty/consts/kind.rs
index de63dae8a3d..becc2b805dd 100644
--- a/compiler/rustc_middle/src/ty/consts/kind.rs
+++ b/compiler/rustc_middle/src/ty/consts/kind.rs
@@ -49,6 +49,7 @@ pub fn new(
 /// Represents a constant in Rust.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, TyEncodable, TyDecodable)]
 #[derive(Hash, HashStable, TypeFoldable, TypeVisitable)]
+#[derive(derive_more::From)]
 pub enum ConstKind<'tcx> {
     /// A const generic parameter.
     Param(ty::ParamConst),
@@ -71,12 +72,19 @@ pub enum ConstKind<'tcx> {
 
     /// A placeholder for a const which could not be computed; this is
     /// propagated to avoid useless error messages.
+    #[from(ignore)]
     Error(ErrorGuaranteed),
 
     /// Expr which contains an expression which has partially evaluated items.
     Expr(Expr<'tcx>),
 }
 
+impl<'tcx> From<ty::ConstVid<'tcx>> for ConstKind<'tcx> {
+    fn from(const_vid: ty::ConstVid<'tcx>) -> Self {
+        InferConst::Var(const_vid).into()
+    }
+}
+
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Hash)]
 #[derive(HashStable, TyEncodable, TyDecodable, TypeVisitable, TypeFoldable)]
 pub enum Expr<'tcx> {