Working

crates/luaffi_impl/src/cdef.rs

@@ -22,7 +22,7 @@ pub fn transform(_args: Args, mut item: Item) -> Result<TokenStream> {
         _ => syn_error!(item, "expected struct or enum"),
     };
 
-    let mod_name = format_ident!("__cdef__{name}");
+    let mod_name = format_ident!("__{name}_cdef");
 
     Ok(quote! {
         #[repr(C)]
@@ -42,23 +42,28 @@ pub fn transform(_args: Args, mut item: Item) -> Result<TokenStream> {
 fn generate_type(ty: &Ident) -> Result<TokenStream> {
     let ffi = ffi_crate();
     let fmt = quote!(::std::format!);
-    let name_fmt = LitStr::new(&format!("{ty}"), ty.span());
-    let cdecl_fmt = LitStr::new(&format!("struct {ty} {{name}}"), ty.span());
+    let name = LitStr::new(&format!("{ty}"), ty.span());
+    let cdecl_fmt = LitStr::new(&format!("struct {ty} {{}}"), ty.span());
 
     Ok(quote! {
         unsafe impl #ffi::Type for #ty {
-            fn name() -> ::std::string::String {
-                #fmt(#name_fmt)
+            fn name() -> impl ::std::fmt::Display {
+                #name
             }
 
-            fn cdecl(name: impl ::std::fmt::Display) -> ::std::string::String {
-                #fmt(#cdecl_fmt)
+            fn cdecl(name: impl ::std::fmt::Display) -> impl ::std::fmt::Display {
+                #fmt(#cdecl_fmt, name)
             }
 
             fn build(b: &mut #ffi::TypeBuilder) {
                 b.cdef::<Self>().metatype::<Self>();
             }
         }
+
+        unsafe impl #ffi::ToFfi for #ty {
+            type To = Self;
+            fn convert(self) -> Self::To { self }
+        }
     })
 }
 
@@ -113,6 +118,11 @@ struct CField {
     attrs: CFieldAttrs,
 }
 
+#[derive(Default)]
+struct CFieldAttrs {
+    opaque: bool,
+}
+
 fn to_cfields(fields: &mut Fields) -> Result<Vec<CField>> {
     match fields {
         Fields::Named(fields) => fields.named.iter_mut(),
@@ -133,11 +143,6 @@ fn to_cfields(fields: &mut Fields) -> Result<Vec<CField>> {
     .collect()
 }
 
-#[derive(Default)]
-struct CFieldAttrs {
-    opaque: bool,
-}
-
 fn parse_attrs(attrs: &mut Vec<Attribute>) -> Result<CFieldAttrs> {
     let mut parsed = CFieldAttrs::default();
     let mut i = 0;