Describe the bug
After updating to 0.15 I can no longer get my filter requiring an argument to be AsRef to build (see reproducer below)
(I'm not convinced I actually need AsRef here, but I couldn't figure any workaround either...)
Anyway I think it's similar to #641 and the macro would need to actively keep track of passed bounds somehow?
I don't have time to look right now, but happy to discuss.
Thanks!
To Reproduce
(this builds with askama 0.14 after removing the filter_fn attribute)
use askama::Template;
mod filters {
use std::convert::Infallible;
#[askama::filter_fn]
pub fn or_dash<'a, T>(
value: &'a Option<T>,
_: &'a dyn askama::Values,
) -> askama::Result<&'a str, Infallible>
where
T: AsRef<str>,
{
Ok(match value {
Some(value) => value.as_ref(),
None => "--",
})
}
}
fn main() {
#[derive(Template)]
#[template(source = r#"{{ foo | or_dash }}"#, ext = "txt")]
struct Template {
foo: Option<String>,
}
let a = Template { foo: None };
assert_eq!(a.render().unwrap(), "--");
let a = Template {
foo: Some("ok".to_string()),
};
assert_eq!(a.render().unwrap(), "ok");
}error[E0599]: the method `as_ref` exists for reference `&T`, but its trait bounds were not satisfied
--> src/main.rs:15:34
|
15 | Some(value) => value.as_ref(),
| ^^^^^^ method cannot be called on `&T` due to unsatisfied trait bounds
|
= note: the following trait bounds were not satisfied:
`T: AsRef<_>`
which is required by `&T: AsRef<_>`
= help: items from traits can only be used if the type parameter is bounded by the trait
help: the following trait defines an item `as_ref`, perhaps you need to restrict type parameter `T` with it:
|
6 | #[askama::filter_fn] AsRef</* T */>
| ++++++++++++++
For more information about this error, try `rustc --explain E0599`.
Askama version
0.15.1
Rust version
1.91.0
Describe the bug
After updating to 0.15 I can no longer get my filter requiring an argument to be AsRef to build (see reproducer below)
(I'm not convinced I actually need AsRef here, but I couldn't figure any workaround either...)
Anyway I think it's similar to #641 and the macro would need to actively keep track of passed bounds somehow?
I don't have time to look right now, but happy to discuss.
Thanks!
To Reproduce
(this builds with askama 0.14 after removing the filter_fn attribute)
Askama version
0.15.1
Rust version
1.91.0