From cfe7ebd463cf4e4e5ba070b1f61ba365ff70300f Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Mon, 21 May 2018 09:13:17 -0700
Subject: [PATCH] Disallow structs w/ lifetime/type parameters

These can't work currently with wasm-bindgen, but maybe one day!

Closes #200
---
 crates/backend/src/ast.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/crates/backend/src/ast.rs b/crates/backend/src/ast.rs
index d493ec5b..b047154f 100644
--- a/crates/backend/src/ast.rs
+++ b/crates/backend/src/ast.rs
@@ -704,6 +704,10 @@ impl ImportType {
 
 impl Struct {
     fn from(s: &mut syn::ItemStruct, _opts: BindgenAttrs) -> Struct {
+        if s.generics.params.len() > 0 {
+            panic!("structs with #[wasm_bindgen] cannot have lifetime or \
+                    type parameters currently");
+        }
         let mut fields = Vec::new();
         if let syn::Fields::Named(names) = &mut s.fields {
             for field in names.named.iter_mut() {