meh
diff --git a/compiler/rustc_middle/src/ty/consts.rs b/compiler/rustc_middle/src/ty/consts.rs
index 0af884a..3f5ada9 100644
--- a/compiler/rustc_middle/src/ty/consts.rs
+++ b/compiler/rustc_middle/src/ty/consts.rs
@@ -10,6 +10,7 @@
mod int;
mod kind;
+mod normalize;
pub use int::*;
pub use kind::*;
diff --git a/compiler/rustc_middle/src/ty/consts/normalize.rs b/compiler/rustc_middle/src/ty/consts/normalize.rs
new file mode 100644
index 0000000..6a0455a
--- /dev/null
+++ b/compiler/rustc_middle/src/ty/consts/normalize.rs
@@ -0,0 +1,59 @@
+use crate::ty::{self, Ty, TyCtxt, TypeFoldable};
+
+impl<'tcx> TyCtxt<'tcx> {
+ pub fn normalize_consts<T: TypeFoldable<'tcx>>(self, value: T) -> T {
+ value.fold_with(&mut ConstNormalizer::new(self))
+ }
+}
+
+pub struct ConstNormalizer<'tcx> {
+ tcx: TyCtxt<'tcx>
+}
+
+impl ConstNormalizer<'_> {
+ pub fn new(tcx: TyCtxt<'_>) -> ConstNormalizer<'_> {
+ ConstNormalizer { tcx }
+ }
+}
+
+impl<'tcx> ty::TypeFolder<'tcx> for ConstNormalizer<'tcx> {
+ fn tcx(&self) -> TyCtxt<'tcx> {
+ self.tcx
+ }
+
+ fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
+ if t.flags().intersects(ty::TypeFlags::HAS_CT_PROJECTION) {
+ t.super_fold_with(self)
+ } else {
+ t
+ }
+ }
+
+ fn fold_const(&mut self, ct: &'tcx ty::Const<'tcx>) -> &'tcx ty::Const<'tcx> {
+ match ct.val {
+ ty::ConstKind::Unevaluated(def, substs, None) => {
+ match self.tcx.mir_abstract_const_opt_const_arg(def) {
+ // FIXME(const_evaluatable_checked): Replace the arguments not used
+ // in the abstract const with dummy ones while keeping everything that is
+ // used.
+ Ok(Some(_abstr_ct)) => self.tcx.mk_const(ty::Const {
+ ty: ct.ty,
+ val: ty::ConstKind::Unevaluated(def, substs, None)
+ }),
+ Ok(None) => {
+ let dummy_substs = ty::InternalSubsts::for_item(self.tcx, def.did, |param, _| {
+ match param.kind {
+ ty::GenericParamDefKind::Lifetime => self.tcx.lifetimes.re_static.into(),
+ ty::GenericParamDefKind::Type { .. } => self.tcx.types.unit.into(),
+ ty::GenericParamDefKind::Const => self.tcx.consts.unit.into(), // TODO
+ }
+ });
+ self.tcx.mk_const(ty::Const { ty: ct.ty, val: ty::ConstKind::Unevaluated(def, dummy_substs, None) })
+ }
+ Err(_) => self.tcx.const_error(ct.ty),
+ }
+ }
+ _ => ct.super_fold_with(self),
+ }
+ }
+}
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 030c291..fd19f6c 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -846,7 +846,9 @@
// by putting it in a query; it would only need the `DefId` as it
// looks at declared field types, not anything substituted.
for field in prefix_fields {
- for arg in tcx.type_of(field.did).walk() {
+ let ty = tcx.normalize_consts(tcx.type_of(field.did));
+
+ for arg in ty.walk() {
if let Some(i) = maybe_unsizing_param_idx(arg) {
if unsizing_params.contains(i) {
return Err(Unimplemented);
