Merge pull request #208 from matoushybl/fix/serde-nostd

Do not use alloc-dependent format! in serde expansion

Author: greyblake

nutype_macros/src/common/gen/traits.rs

@@ -294,8 +294,7 @@ pub fn gen_impl_trait_serde_deserialize(
         quote! {
             #type_name::try_new(raw_value).map_err(|validation_error| {
                 // Add a hint about which type is causing the error,
-                let err_msg = format!("{validation_error} Expected valid {}", #type_name_str);
-                <DE::Error as serde::de::Error>::custom(err_msg)
+                <DE::Error as serde::de::Error>::custom(core::format_args!("{validation_error} Expected valid {}", #type_name_str))
             })
         }
     } else {