if first type bound isn't Into<T> auto-box it

1 files changed, 3 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 4512141..99abfdb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -365,6 +365,9 @@ impl TypeTransform {
     fn convert(&self, arg: proc_macro2::TokenStream) -> proc_macro2::TokenStream {
         match self {
             TypeTransform::Into => quote! {#arg.into()},
+            TypeTransform::Box(box_type) => {
+                quote! {Box::new(#arg) as #box_type}
+            }
             TypeTransform::Map(opt) => {
                 let inner = opt.convert(quote!(x));
                 quote! {#arg.map(|x| #inner)}