xml: XmlRoot add namespace checking

crates/xml/derive/src/de/attrs.rs

@@ -36,6 +36,7 @@ pub struct StructAttrs {
     pub container: ContainerAttrs,
 
     pub root: Option<LitByteStr>,
+    pub ns: Option<LitByteStr>,
     pub allow_invalid: Flag,
 }
 

crates/xml/derive/src/de/de_struct.rs

@@ -51,9 +51,14 @@ impl NamedStruct {
         let (impl_generics, type_generics, where_clause) = self.generics.split_for_impl();
         let ident = &self.ident;
         let root = self.attrs.root.as_ref().expect("No root attribute found");
+        let ns = match &self.attrs.ns {
+            Some(ns) => quote! { Some(#ns) },
+            None => quote! { None },
+        };
         quote! {
             impl #impl_generics ::rustical_xml::XmlRoot for #ident #type_generics #where_clause {
                 fn root_tag() -> &'static [u8] { #root }
+                fn root_ns() -> Option<&'static [u8]> { #ns }
             }
         }
     }