Trait bound not satisfied

[shut mauve]

-errors

[slow stirrup]

If you're getting large or confusing errors please post the full error message from cargo check in a code block instead of the errors in your IDE so that we can understand your problem better:

```rust
// error from cargo check here
```

[shut mauve]

you need to constrain <A as App>::Message to be Message

where
  A: App<Message = Message>

don't assign closures to variables

?play ```rs
let x = |x: &_| x;
x(&42);

[vale furnace]

error: lifetime may not live long enough
 --> src/main.rs:2:17
  |
2 | let x = |x: &_| x;
  |             - - ^ returning this value requires that `'1` must outlive `'2`
  |             | |
  |             | return type of closure is &'2 i32
  |             let's call the lifetime of this reference `'1````

[shut mauve]

the lifetimes aren't inferred as you may expect

what is the signature of header_bar and set_header?

its the impl Widget<Message> + 'static

the 'static in particular

fn header_bar(&self) -> impl Widget<Self::Message>; needs it then also

fn header_bar(&self) -> impl Widget<Self::Message> + 'static;

whats the error?

this is part of a trait right? (header_bar)

you need to add the + 'static to every impl