() not Serializable

[Sushisource]

Hey all, starting playing around with this, looks very cool.

Ran into the problem in the title almost right away though, which was rather surprising. I assume just an oversight, but would be nice to have.

Additionally when I first tried writing a generic Serializable struct, I added bounds to the generic for T: Serializable which I would expect to be necessary, but the macro seems to break on that (and if you remove it, appears to silently enforce it). It'd be good to allow that, or have a more explicit error.

Thanks!

[emschwartz]

Based on @arendjr adding the good first issue label, I think he's saying that yes this is indeed an oversight :) Thanks for reporting the issue!

[sagacity]

I'll pick this up.

[sagacity]

@Sushisource could you share the struct definition that wasn't working for you?

[Sushisource]

Even just this will do it:

use fp_bindgen::prelude::*;

#[derive(Serializable)]
struct Foo {
    hi: ()
}

Results in:

λ  cargo build
   Compiling rust-scratch v0.1.0 (/mnt/chonky/dev/rust-scratch)
error: proc-macro derive panicked
 --> src/main.rs:9:10
  |
9 | #[derive(Serializable)]
  |          ^^^^^^^^^^^^
  |
  = help: message: Only value types are supported. Incompatible type in struct field: Field { attrs: [], vis: Inherited, ident: Some(Ident { ident: "hi", span: #0 bytes(158..160) }), colon_token: Some(Colon), ty: Tuple(TypeTuple { paren_token: Paren, elems: [] }) }

[sagacity]

@Sushisource thanks for sharing. I'm currently doing some work to allow unit types to be used in return types (e.g. Result<(), Error>). Do you have a use case for having unit fields in a struct? Otherwise I'm not sure we'd want to support that.

[Sushisource]

Yeah, the use case is a generic struct like this:

use fp_bindgen::prelude::*;

#[derive(Serializable)]
struct Foo<T> {
    hi: T
}

Where some reification of that struct might reasonably want to use the unit type because it happens not to care about populating that field meaningfully