1 files changed, 32 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/ty/generics.rs b/compiler/rustc_middle/src/ty/generics.rs
index 8e6c1cd4b..888ee1d23 100644
--- a/compiler/rustc_middle/src/ty/generics.rs
+++ b/compiler/rustc_middle/src/ty/generics.rs
@@ -79,6 +79,10 @@ impl GenericParamDef {
         }
     }
 
+    pub fn is_host_effect(&self) -> bool {
+        matches!(self.kind, GenericParamDefKind::Const { is_host_effect: true, .. })
+    }
+
     pub fn default_value<'tcx>(
         &self,
         tcx: TyCtxt<'tcx>,
@@ -233,6 +237,20 @@ impl<'tcx> Generics {
         }
     }
 
+    /// Returns the `GenericParamDef` with the given index if available.
+    pub fn opt_param_at(
+        &'tcx self,
+        param_index: usize,
+        tcx: TyCtxt<'tcx>,
+    ) -> Option<&'tcx GenericParamDef> {
+        if let Some(index) = param_index.checked_sub(self.parent_count) {
+            self.params.get(index)
+        } else {
+            tcx.generics_of(self.parent.expect("parent_count > 0 but no parent?"))
+                .opt_param_at(param_index, tcx)
+        }
+    }
+
     pub fn params_to(&'tcx self, param_index: usize, tcx: TyCtxt<'tcx>) -> &'tcx [GenericParamDef] {
         if let Some(index) = param_index.checked_sub(self.parent_count) {
             &self.params[..index]
@@ -264,6 +282,20 @@ impl<'tcx> Generics {
         }
     }
 
+    /// Returns the `GenericParamDef` associated with this `ParamTy` if it belongs to this
+    /// `Generics`.
+    pub fn opt_type_param(
+        &'tcx self,
+        param: &ParamTy,
+        tcx: TyCtxt<'tcx>,
+    ) -> Option<&'tcx GenericParamDef> {
+        let param = self.opt_param_at(param.index as usize, tcx)?;
+        match param.kind {
+            GenericParamDefKind::Type { .. } => Some(param),
+            _ => None,
+        }
+    }
+
     /// Returns the `GenericParamDef` associated with this `ParamConst`.
     pub fn const_param(&'tcx self, param: &ParamConst, tcx: TyCtxt<'tcx>) -> &GenericParamDef {
         let param = self.param_at(param.index as usize, tcx);