address review

Author: b-naber

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1819,7 +1819,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     _ => None,
                 },
                 ConstantKind::Unevaluated(uv, _) => Some(uv),
-                _ => None,
+                ConstantKind::Val(..) => None,
             };
 
             if let Some(uv) = maybe_uneval {

compiler/rustc_middle/src/mir/mod.rs

@@ -2062,7 +2062,7 @@ pub enum ConstantKind<'tcx> {
     /// This constant came from the type system
     Ty(ty::Const<'tcx>),
 
-    /// An unevaluated constant that cannot go back into the type system.
+    /// An unevaluated mir constant which is not part of the type system.
     Unevaluated(ty::Unevaluated<'tcx, Option<Promoted>>, Ty<'tcx>),
 
     /// This constant cannot go back into the type system, as it represents

compiler/rustc_middle/src/mir/visit.rs

@@ -1077,20 +1077,12 @@ macro_rules! visit_place_fns {
                         location,
                     );
 
-                    if new_local == local {
-                        None
-                    } else {
-                        Some(PlaceElem::Index(new_local))
-                    }
+                    if new_local == local { None } else { Some(PlaceElem::Index(new_local)) }
                 }
                 PlaceElem::Field(field, ty) => {
                     let mut new_ty = ty;
                     self.visit_ty(&mut new_ty, TyContext::Location(location));
-                    if ty != new_ty {
-                        Some(PlaceElem::Field(field, new_ty))
-                    } else {
-                        None
-                    }
+                    if ty != new_ty { Some(PlaceElem::Field(field, new_ty)) } else { None }
                 }
                 PlaceElem::Deref
                 | PlaceElem::ConstantIndex { .. }

compiler/rustc_mir_transform/src/const_prop_lint.rs

@@ -299,7 +299,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
                 let err = ConstEvalErr::new(&self.ecx, error, Some(c.span));
                 if let Some(lint_root) = self.lint_root(source_info) {
                     let lint_only = match c.literal {
-                        ConstantKind::Ty(_) => c.literal.needs_subst(),
+                        ConstantKind::Ty(ct) => ct.needs_subst(),
                         ConstantKind::Unevaluated(
                             ty::Unevaluated { def: _, substs: _, promoted: Some(_) },
                             _,