From 7d340942a0c77ab4c59575273bfa555642a6b5e2 Mon Sep 17 00:00:00 2001
From: Jonas Platte <jplatte+git@posteo.de>
Date: Tue, 26 Nov 2019 22:36:58 +0100
Subject: [PATCH] Error when derive(Outgoing) is used on a type with generics

---
 ruma-api-macros/src/derive_outgoing.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/ruma-api-macros/src/derive_outgoing.rs b/ruma-api-macros/src/derive_outgoing.rs
index 8d8e866b..aec49740 100644
--- a/ruma-api-macros/src/derive_outgoing.rs
+++ b/ruma-api-macros/src/derive_outgoing.rs
@@ -12,6 +12,13 @@ mod wrap_incoming;
 use wrap_incoming::Meta;
 
 pub fn expand_derive_outgoing(input: DeriveInput) -> syn::Result<TokenStream> {
+    if !input.generics.params.is_empty() {
+        return Err(syn::Error::new_spanned(
+            input.generics,
+            "derive(Outgoing) doesn't currently support types with generics!",
+        ));
+    }
+
     let derive_deserialize = if no_deserialize_in_attrs(&input.attrs) {
         TokenStream::new()
     } else {