diff options
| -rw-r--r-- | src/librustc/middle/ty.rs | 4 | ||||
| -rw-r--r-- | src/librustc_typeck/check/_match.rs | 14 |
2 files changed, 16 insertions, 2 deletions
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs index c720032bef2..0d853295502 100644 --- a/src/librustc/middle/ty.rs +++ b/src/librustc/middle/ty.rs @@ -1779,6 +1779,10 @@ impl<'tcx> Generics<'tcx> { !self.regions.is_empty_in(space) } + pub fn is_empty(&self) -> bool { + self.types.is_empty() && self.regions.is_empty() + } + pub fn to_bounds(&self, tcx: &ty::ctxt<'tcx>, substs: &Substs<'tcx>) -> GenericBounds<'tcx> { GenericBounds { diff --git a/src/librustc_typeck/check/_match.rs b/src/librustc_typeck/check/_match.rs index 7ff0e1758f5..49627120d22 100644 --- a/src/librustc_typeck/check/_match.rs +++ b/src/librustc_typeck/check/_match.rs @@ -103,8 +103,18 @@ pub fn check_pat<'a, 'tcx>(pcx: &pat_ctxt<'a, 'tcx>, ast::PatEnum(..) | ast::PatIdent(..) if pat_is_const(&tcx.def_map, pat) => { let const_did = tcx.def_map.borrow()[pat.id].clone().def_id(); let const_scheme = ty::lookup_item_type(tcx, const_did); - fcx.write_ty(pat.id, const_scheme.ty); - demand::suptype(fcx, pat.span, expected, const_scheme.ty); + assert!(const_scheme.generics.is_empty()); + let const_ty = pcx.fcx.instantiate_type_scheme(pat.span, + &Substs::empty(), + &const_scheme.ty); + fcx.write_ty(pat.id, const_ty); + + // FIXME(#20489) -- we should limit the types here to scalars or something! + + // As with PatLit, what we really want here is that there + // exist a LUB, but for the cases that can occur, subtype + // is good enough. + demand::suptype(fcx, pat.span, expected, const_ty); } ast::PatIdent(bm, ref path, ref sub) if pat_is_binding(&tcx.def_map, pat) => { let typ = fcx.local_ty(pat.span, pat.id); |