Constants carry their type with them

Author: oli-obk

src/librustc/ty/sty.rs

@@ -2060,10 +2060,9 @@ impl<'tcx> Const<'tcx> {
     pub fn unwrap_bits(
         &self,
         tcx: TyCtxt<'_, '_, '_>,
-        ty: ParamEnvAnd<'tcx, Ty<'tcx>>,
     ) -> u128 {
-        self.assert_bits(tcx, ty).unwrap_or_else(||
-            bug!("expected bits of {}, got {:#?}", ty.value, self))
+        self.assert_bits(tcx, ParamEnv::empty().and(self.ty)).unwrap_or_else(||
+            bug!("expected bits of {}, got {:#?}", self.ty, self))
     }
 
     #[inline]

src/librustc_mir/build/matches/mod.rs

@@ -978,15 +978,14 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
         // available
         match test.kind {
             TestKind::SwitchInt {
-                switch_ty,
                 ref mut options,
                 ref mut indices,
+                ..
             } => {
                 for candidate in candidates.iter() {
                     if !self.add_cases_to_switch(
                         &match_pair.place,
                         candidate,
-                        switch_ty,
                         options,
                         indices,
                     ) {

src/librustc_mir/build/matches/test.rs

@@ -112,7 +112,6 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     pub fn add_cases_to_switch<'pat>(&mut self,
                                      test_place: &Place<'tcx>,
                                      candidate: &Candidate<'pat, 'tcx>,
-                                     switch_ty: Ty<'tcx>,
                                      options: &mut Vec<u128>,
                                      indices: &mut FxHashMap<&'tcx ty::Const<'tcx>, usize>)
                                      -> bool
@@ -124,10 +123,9 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
 
         match *match_pair.pattern.kind {
             PatternKind::Constant { value } => {
-                let switch_ty = ty::ParamEnv::empty().and(switch_ty);
                 indices.entry(value)
                        .or_insert_with(|| {
-                           options.push(value.unwrap_bits(self.hir.tcx(), switch_ty));
+                           options.push(value.unwrap_bits(self.hir.tcx()));
                            options.len() - 1
                        });
                 true

src/librustc_mir/hair/pattern/_match.rs

@@ -1364,7 +1364,7 @@ fn slice_pat_covered_by_constructor<'tcx>(
     {
         match pat.kind {
             box PatternKind::Constant { value } => {
-                let b = value.unwrap_bits(tcx, ty::ParamEnv::empty().and(pat.ty));
+                let b = value.unwrap_bits(tcx);
                 assert_eq!(b as u8 as u128, b);
                 if b as u8 != *ch {
                     return Ok(false);