Closed
Description
openedon May 6, 2021
Given the following code: Rust Playground
fn main() {
let f = Fancy{};
let o = Other::new(f);
// ^^^^^^ needs to borrow here but the error does not say so
}
struct Fancy {}
impl <'a> SomeTrait for &'a Fancy {
}
trait SomeTrait {}
struct Other<'a, G> {
a: &'a str,
g: G,
}
// Broadly copied from https://docs.rs/petgraph/0.5.1/src/petgraph/dot.rs.html#70
impl<'a, G> Other<'a, G>
where
G: SomeTrait,
{
pub fn new(g: G) -> Self {
Other {
a: "hi",
g: g,
}
}
}The current output is:
error[E0277]: the trait bound `Fancy: SomeTrait` is not satisfied
--> src/main.rs:3:24
|
3 | let o = Other::new(f);
| ^ the trait `SomeTrait` is not implemented for `Fancy`
...
24 | pub fn new(g: G) -> Self {
| ------------------------ required by `Other::<'a, G>::new`
|
= help: the following implementations were found:
<&'a Fancy as SomeTrait>
Not really sure about the precise wording, but the help section should suggest borrowing f when passing it to Other::new(f) as rustc has figured out that there is an impl that just differs by the ownership.
The output is the same on Nightly.
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