empty struct fails with proc macro

[drahnr]

Hi djc,

not sure if this is a general rust issue or an implementation detail in askama (I might be just too silly to pass the right terms to my fav search engine).

#[derive(Template)];
struct Index; // no struct members

error: proc-macro derive panicked
  --> src/main.rs:18:10
   |
18 | #[derive(Template)]
   |          ^^^^^^^^
   |
   = help: message: derive(Template) only works for struct items

error: aborting due to previous error

error: Could not compile `cantaloupe`.

To learn more, run the command again with --verbose.

---

$ rustc --version
rustc 1.27.0 (3eda71b00 2018-06-19)

[djc]

This is Askama-specific. It probably works if you make it struct Index {};?

[drahnr]

Yes indeed! Adding {} makes it compile (if I also add either a new or default impl since Index.render().unwrap() won't work anymore).

[djc]

You can similarly do Index {}.render().unwrap() (maybe needs some extra parentheses).

[drahnr]

True, didn't think of that.

EDIT:

Just verified: Works as expected.

[djc]

So I've decided to lift the restrictions here, so you can now use any kind of struct as the context.

[djc]

And thanks for reporting!

[drahnr]

Awesome, thank you! As always, incredible turn around times :)

[djc]

It helps that we're timezone-aligned 😊