Produce error message for use of flatten in tuple structs

2026-04-29 09:27:56 +00:00 · 2018-04-01 22:11:21 +02:00
parent 9c659d9d86
commit 77376f39ea
3 changed files with 42 additions and 1 deletions
@@ -47,11 +47,20 @@ fn check_flatten(cx: &Ctxt, cont: &Container) {
        Data::Enum(_) => {
            assert!(!cont.attrs.has_flatten());
        }
-        Data::Struct(_, _) => {
+        Data::Struct(style, _) => {
            for field in cont.data.all_fields() {
                if !field.attrs.flatten() {
                    continue;
                }
+                match style {
+                    Style::Tuple => {
+                        cx.error("#[serde(flatten)] cannot be used on tuple structs");
+                    }
+                    Style::Newtype => {
+                        cx.error("#[serde(flatten)] cannot be used on newtype structs");
+                    }
+                    _ => {}
+                }
                if field.attrs.skip_serializing() {
                    cx.error(
                        "#[serde(flatten] can not be combined with \