a revelation

Author: xacrimon

compiler/rustc_mir_build/src/builder/matches/match_pair.rs

@@ -152,8 +152,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     ) -> MatchPairTree<'pat, 'tcx> {
         let tcx = self.tcx;
 
-        // TODO: should these be arrays?
-        let (const_ty, pat_ty) = match src_pat_ty.kind() {
+        tracing::warn!("source pattern type: {:?}", src_pat_ty);
+        let (const_ty, pat_ty) = match src_pat_ty.kind() { // wait is source path the wrong thing to care about?
             ty::Slice(_) => (
                 Ty::new_imm_ref(
                     tcx,
@@ -168,11 +168,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     tcx.lifetimes.re_erased,
                     Ty::new_array(tcx, elem_ty, subslice_len),
                 ),
-                Ty::new_array(tcx, elem_ty, subslice_len),
+                Ty::new_array(tcx, elem_ty, subslice_len), // WRONG TYPE with too short array len for the move
             ),
             _ => todo!(),
         };
 
+        tracing::warn!("const and new pattern type: {:?}, {:?}", const_ty, pat_ty);
+
         let r#const = ty::Const::new(tcx, ty::ConstKind::Value(const_ty, valtree));
         let r#const2 = Const::Ty(const_ty, r#const);
 

library/core/src/cmp.rs

@@ -26,6 +26,7 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 mod bytewise;
+#[cfg(not(bootstrap))]
 mod pattern;
 pub(crate) use bytewise::BytewiseEq;