Move GenericArgKind::as_{type,const,region} to GenericArg

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -1181,7 +1181,7 @@ fn build_generic_type_param_di_nodes<'ll, 'tcx>(
             let names = get_parameter_names(cx, generics);
             let template_params: SmallVec<_> = iter::zip(substs, names)
                 .filter_map(|(kind, name)| {
-                    kind.unpack().as_type().map(|ty| {
+                    kind.as_type().map(|ty| {
                         let actual_type =
                             cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
                         let actual_type_di_node = type_di_node(cx, actual_type);

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -461,7 +461,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                 let names = get_parameter_names(cx, generics);
                 iter::zip(substs, names)
                     .filter_map(|(kind, name)| {
-                        kind.unpack().as_type().map(|ty| {
+                        kind.as_type().map(|ty| {
                             let actual_type =
                                 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
                             let actual_type_metadata = type_di_node(cx, actual_type);

compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs

@@ -250,7 +250,7 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
 
     fn ty_infer(&self, param: Option<&ty::GenericParamDef>, span: Span) -> Ty<'tcx> {
         match param {
-            Some(param) => self.var_for_def(span, param).unpack().as_type().unwrap(),
+            Some(param) => self.var_for_def(span, param).as_type().unwrap(),
             None => self.next_ty_var(TypeVariableOrigin {
                 kind: TypeVariableOriginKind::TypeInference,
                 span,
@@ -265,7 +265,7 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
         span: Span,
     ) -> Const<'tcx> {
         match param {
-            Some(param) => self.var_for_def(span, param).unpack().as_const().unwrap(),
+            Some(param) => self.var_for_def(span, param).as_const().unwrap(),
             None => self.next_const_var(
                 ty,
                 ConstVariableOrigin { kind: ConstVariableOriginKind::ConstInference, span },

compiler/rustc_middle/src/ty/subst.rs

@@ -103,30 +103,6 @@ impl<'tcx> GenericArgKind<'tcx> {
 
         GenericArg { ptr: unsafe { NonZeroUsize::new_unchecked(ptr | tag) }, marker: PhantomData }
     }
-
-    #[inline]
-    pub fn as_type(self) -> Option<Ty<'tcx>> {
-        match self {
-            GenericArgKind::Type(ty) => Some(ty),
-            _ => None,
-        }
-    }
-
-    #[inline]
-    pub fn as_region(self) -> Option<ty::Region<'tcx>> {
-        match self {
-            GenericArgKind::Lifetime(re) => Some(re),
-            _ => None,
-        }
-    }
-
-    #[inline]
-    pub fn as_const(self) -> Option<ty::Const<'tcx>> {
-        match self {
-            GenericArgKind::Const(ct) => Some(ct),
-            _ => None,
-        }
-    }
 }
 
 impl<'tcx> fmt::Debug for GenericArg<'tcx> {
@@ -204,30 +180,45 @@ impl<'tcx> GenericArg<'tcx> {
         }
     }
 
+    #[inline]
+    pub fn as_type(self) -> Option<Ty<'tcx>> {
+        match self.unpack() {
+            GenericArgKind::Type(ty) => Some(ty),
+            _ => None,
+        }
+    }
+
+    #[inline]
+    pub fn as_region(self) -> Option<ty::Region<'tcx>> {
+        match self.unpack() {
+            GenericArgKind::Lifetime(re) => Some(re),
+            _ => None,
+        }
+    }
+
+    #[inline]
+    pub fn as_const(self) -> Option<ty::Const<'tcx>> {
+        match self.unpack() {
+            GenericArgKind::Const(ct) => Some(ct),
+            _ => None,
+        }
+    }
+
     /// Unpack the `GenericArg` as a region when it is known certainly to be a region.
     pub fn expect_region(self) -> ty::Region<'tcx> {
-        match self.unpack() {
+        self.as_region().unwrap_or_else(|| bug!("expected a region, but found another kind"))
-            GenericArgKind::Lifetime(lt) => lt,
-            _ => bug!("expected a region, but found another kind"),
-        }
     }
 
     /// Unpack the `GenericArg` as a type when it is known certainly to be a type.
     /// This is true in cases where `Substs` is used in places where the kinds are known
     /// to be limited (e.g. in tuples, where the only parameters are type parameters).
     pub fn expect_ty(self) -> Ty<'tcx> {
-        match self.unpack() {
+        self.as_type().unwrap_or_else(|| bug!("expected a type, but found another kind"))
-            GenericArgKind::Type(ty) => ty,
-            _ => bug!("expected a type, but found another kind"),
-        }
     }
 
     /// Unpack the `GenericArg` as a const when it is known certainly to be a const.
     pub fn expect_const(self) -> ty::Const<'tcx> {
-        match self.unpack() {
+        self.as_const().unwrap_or_else(|| bug!("expected a const, but found another kind"))
-            GenericArgKind::Const(c) => c,
-            _ => bug!("expected a const, but found another kind"),
-        }
     }
 
     pub fn is_non_region_infer(self) -> bool {
@@ -403,17 +394,17 @@ impl<'tcx> InternalSubsts<'tcx> {
 
     #[inline]
     pub fn types(&'tcx self) -> impl DoubleEndedIterator<Item = Ty<'tcx>> + 'tcx {
-        self.iter().filter_map(|k| k.unpack().as_type())
+        self.iter().filter_map(|k| k.as_type())
     }
 
     #[inline]
     pub fn regions(&'tcx self) -> impl DoubleEndedIterator<Item = ty::Region<'tcx>> + 'tcx {
-        self.iter().filter_map(|k| k.unpack().as_region())
+        self.iter().filter_map(|k| k.as_region())
     }
 
     #[inline]
     pub fn consts(&'tcx self) -> impl DoubleEndedIterator<Item = ty::Const<'tcx>> + 'tcx {
-        self.iter().filter_map(|k| k.unpack().as_const())
+        self.iter().filter_map(|k| k.as_const())
     }
 
     #[inline]
@@ -429,17 +420,13 @@ impl<'tcx> InternalSubsts<'tcx> {
     #[inline]
     #[track_caller]
     pub fn type_at(&self, i: usize) -> Ty<'tcx> {
-        self[i]
+        self[i].as_type().unwrap_or_else(|| bug!("expected type for param #{} in {:?}", i, self))
-            .unpack()
-            .as_type()
-            .unwrap_or_else(|| bug!("expected type for param #{} in {:?}", i, self))
     }
 
     #[inline]
     #[track_caller]
     pub fn region_at(&self, i: usize) -> ty::Region<'tcx> {
         self[i]
-            .unpack()
             .as_region()
             .unwrap_or_else(|| bug!("expected region for param #{} in {:?}", i, self))
     }
@@ -447,10 +434,7 @@ impl<'tcx> InternalSubsts<'tcx> {
     #[inline]
     #[track_caller]
     pub fn const_at(&self, i: usize) -> ty::Const<'tcx> {
-        self[i]
+        self[i].as_const().unwrap_or_else(|| bug!("expected const for param #{} in {:?}", i, self))
-            .unpack()
-            .as_const()
-            .unwrap_or_else(|| bug!("expected const for param #{} in {:?}", i, self))
     }
 
     #[inline]

compiler/rustc_mir_transform/src/function_item_references.rs

@@ -45,7 +45,7 @@ impl<'tcx> Visitor<'tcx> for FunctionItemRefChecker<'_, 'tcx> {
                 // Handle calls to `transmute`
                 if self.tcx.is_diagnostic_item(sym::transmute, def_id) {
                     let arg_ty = args[0].ty(self.body, self.tcx);
-                    for inner_ty in arg_ty.walk().filter_map(|arg| arg.unpack().as_type()) {
+                    for inner_ty in arg_ty.walk().filter_map(|arg| arg.as_type()) {
                         if let Some((fn_id, fn_substs)) =
                             FunctionItemRefChecker::is_fn_ref(inner_ty)
                         {
@@ -80,7 +80,7 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
                 let arg_defs = self.tcx.fn_sig(def_id).subst_identity().skip_binder().inputs();
                 for (arg_num, arg_def) in arg_defs.iter().enumerate() {
                     // For all types reachable from the argument type in the fn sig
-                    for inner_ty in arg_def.walk().filter_map(|arg| arg.unpack().as_type()) {
+                    for inner_ty in arg_def.walk().filter_map(|arg| arg.as_type()) {
                         // If the inner type matches the type bound by `Pointer`
                         if inner_ty == bound_ty {
                             // Do a substitution using the parameters from the callsite