Move ParamTerm out of rustc_middle.

It's only used in `rustc_hir_typeck`.

Author: nnethercote

compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs

@@ -17,6 +17,21 @@ enum ClauseFlavor {
     Const,
 }
 
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+enum ParamTerm {
+    Ty(ty::ParamTy),
+    Const(ty::ParamConst),
+}
+
+impl ParamTerm {
+    fn index(self) -> usize {
+        match self {
+            ParamTerm::Ty(ty) => ty.index as usize,
+            ParamTerm::Const(ct) => ct.index as usize,
+        }
+    }
+}
+
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub(crate) fn adjust_fulfillment_error_for_expr_obligation(
         &self,
@@ -77,17 +92,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 _ => return false,
             };
 
-        let find_param_matching = |matches: &dyn Fn(ty::ParamTerm) -> bool| {
+        let find_param_matching = |matches: &dyn Fn(ParamTerm) -> bool| {
             predicate_args.iter().find_map(|arg| {
                 arg.walk().find_map(|arg| {
                     if let ty::GenericArgKind::Type(ty) = arg.kind()
                         && let ty::Param(param_ty) = *ty.kind()
-                        && matches(ty::ParamTerm::Ty(param_ty))
+                        && matches(ParamTerm::Ty(param_ty))
                     {
                         Some(arg)
                     } else if let ty::GenericArgKind::Const(ct) = arg.kind()
                         && let ty::ConstKind::Param(param_ct) = ct.kind()
-                        && matches(ty::ParamTerm::Const(param_ct))
+                        && matches(ParamTerm::Const(param_ct))
                     {
                         Some(arg)
                     } else {
@@ -106,14 +121,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // from a trait or impl, for example.
         let mut fallback_param_to_point_at = find_param_matching(&|param_term| {
             self.tcx.parent(generics.param_at(param_term.index(), self.tcx).def_id) != def_id
-                && !matches!(param_term, ty::ParamTerm::Ty(ty) if ty.name == kw::SelfUpper)
+                && !matches!(param_term, ParamTerm::Ty(ty) if ty.name == kw::SelfUpper)
         });
         // Finally, the `Self` parameter is possibly the reason that the predicate
         // is unsatisfied. This is less likely to be true for methods, because
         // method probe means that we already kinda check that the predicates due
         // to the `Self` type are true.
         let mut self_param_to_point_at = find_param_matching(
-            &|param_term| matches!(param_term, ty::ParamTerm::Ty(ty) if ty.name == kw::SelfUpper),
+            &|param_term| matches!(param_term, ParamTerm::Ty(ty) if ty.name == kw::SelfUpper),
         );
 
         // Finally, for ambiguity-related errors, we actually want to look

compiler/rustc_middle/src/ty/mod.rs

@@ -673,21 +673,6 @@ impl<'tcx> TermKind<'tcx> {
     }
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
-pub enum ParamTerm {
-    Ty(ParamTy),
-    Const(ParamConst),
-}
-
-impl ParamTerm {
-    pub fn index(self) -> usize {
-        match self {
-            ParamTerm::Ty(ty) => ty.index as usize,
-            ParamTerm::Const(ct) => ct.index as usize,
-        }
-    }
-}
-
 #[derive(Copy, Clone, Eq, PartialEq, Debug)]
 pub enum TermVid {
     Ty(ty::TyVid),