Pass where clause on struct through bitsize macros

bilge-impl/src/bitsize.rs

@@ -121,38 +121,22 @@ fn analyze_enum(bitsize: BitSize, variants: Iter<Variant>) {
 }
 
 fn generate_struct(item: &ItemStruct, declared_bitsize: u8) -> TokenStream {
-    let ItemStruct {
-        vis,
-        ident,
-        fields,
-        generics,
-        ..
-    } = item;
+    let ItemStruct { ident, fields, generics, .. } = item;
     let declared_bitsize = declared_bitsize as usize;
 
     let computed_bitsize = fields.iter().fold(quote!(0), |acc, next| {
         let field_size = shared::generate_type_bitsize(&next.ty);
         quote!(#acc + #field_size)
     });
 
-    // we could remove this if the whole struct gets passed
-    let is_tuple_struct = fields.iter().any(|field| field.ident.is_none());
-    let fields_def = if is_tuple_struct {
-        let fields = fields.iter();
-        quote! {
-            ( #(#fields,)* );
-        }
-    } else {
-        let fields = fields.iter();
-        quote! {
-            { #(#fields,)* }
-        }
-    };
+    // The only part of the struct we don't want to pass through are the attributes
+    let mut item = item.clone();
+    item.attrs = Vec::new();
 
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
 
     quote! {
-        #vis struct #ident #generics #fields_def
+        #item
 
         impl #impl_generics #ident #ty_generics #where_clause {
             // constness: when we get const blocks evaluated at compile time, add a const computed_bitsize

bilge-impl/src/bitsize_internal.rs

@@ -92,7 +92,7 @@ fn generate_struct(struct_data: &ItemStruct, arb_int: &TokenStream) -> TokenStre
     let const_ = if cfg!(feature = "nightly") { quote!(const) } else { quote!() };
 
     quote! {
-        #vis struct #ident #generics {
+        #vis struct #ident #generics #where_clause {
             /// WARNING: modifying this value directly can break invariants
             value: #arb_int,
             _phantom: ::core::marker::PhantomData<(#(#phantom),*)>