is_closure_like

compiler/rustc_hir/src/def.rs

@@ -115,6 +115,12 @@ pub enum DefKind {
     Impl {
         of_trait: bool,
     },
+    /// A closure, coroutine, or coroutine-closure.
+    ///
+    /// These are all represented with the same `ExprKind::Closure` in the AST and HIR,
+    /// which makes it difficult to distinguish these during def collection. Therefore,
+    /// we treat them all the same, and code which needs to distinguish them can match
+    /// or `hir::ClosureKind` or `type_of`.
     Closure,
 }