Fix slice restriction to exclude slice of CxxString
diff --git a/syntax/check.rs b/syntax/check.rs
index 44be4dc..fbe6fbc 100644
--- a/syntax/check.rs
+++ b/syntax/check.rs
@@ -236,7 +236,7 @@
fn check_type_slice_ref(cx: &mut Check, ty: &SliceRef) {
let supported = match &ty.inner {
Type::Str(_) | Type::SliceRef(_) => false,
- Type::Ident(ident) => !is_opaque_cxx(cx, &ident.rust),
+ Type::Ident(ident) => !is_unsized(cx, &ty.inner) || cx.types.rust.contains(&ident.rust),
element => !is_unsized(cx, element),
};