fix rustdoc

Author: lcnr

src/librustdoc/clean/mod.rs

@@ -1335,17 +1335,23 @@ impl Clean<Type> for hir::Ty<'_> {
             }
             TyKind::Slice(ref ty) => Slice(box ty.clean(cx)),
             TyKind::Array(ref ty, ref length) => {
-                let def_id = cx.tcx.hir().local_def_id(length.hir_id);
-                // NOTE(min_const_generics): We can't use `const_eval_poly` for constants
-                // as we currently do not supply the parent generics to anonymous constants
-                // but do allow `ConstKind::Param`.
-                //
-                // `const_eval_poly` tries to to first substitute generic parameters which
-                // results in an ICE while manually constructing the constant and using `eval`
-                // does nothing for `ConstKind::Param`.
-                let ct = ty::Const::from_anon_const(cx.tcx, def_id);
-                let param_env = cx.tcx.param_env(def_id);
-                let length = print_const(cx, ct.eval(cx.tcx, param_env));
+                let length = match length {
+                    hir::ArrayLen::Infer(_, _) => "_".to_string(),
+                    hir::ArrayLen::Body(anon_const) => {
+                        let def_id = cx.tcx.hir().local_def_id(anon_const.hir_id);
+                        // NOTE(min_const_generics): We can't use `const_eval_poly` for constants
+                        // as we currently do not supply the parent generics to anonymous constants
+                        // but do allow `ConstKind::Param`.
+                        //
+                        // `const_eval_poly` tries to to first substitute generic parameters which
+                        // results in an ICE while manually constructing the constant and using `eval`
+                        // does nothing for `ConstKind::Param`.
+                        let ct = ty::Const::from_anon_const(cx.tcx, def_id);
+                        let param_env = cx.tcx.param_env(def_id);
+                        print_const(cx, ct.eval(cx.tcx, param_env))
+                    }
+                };
+
                 Array(box ty.clean(cx), length)
             }
             TyKind::Tup(tys) => Tuple(tys.iter().map(|x| x.clean(cx)).collect()),