Hi everyone, I encounter this error and tried to solve it but no progress. The context is that I try to return an async callback from a function.
// async callback
let callback = || async {...}
// a function that return the call back
pub fn example() -> (fn() -> dyn futures::Future<Output = DekuValue>){
...
return (callback);
}
And it shows this error
Return a Box<dyn futures::Future<Output = DekuValue>> instead. Trait objects can only be returned behind some kind of pointer.
I did try the solution but wonder if there was anything missed. It throws another error.
What does the code look like? You have to box the whole async block
The code is written inside a procedural macro and it looks like this. The idea is I wrap the macro around a function and it would turn a function into an async function, then return it back.
#codeblock: the body content of the wrapped function#vis: visibility of function#fn_token: function token fn
#ident: function name
The closure needs to be something like
|| Box::new(async { #codeblock })
You have to do the boxing explicitly, it isn't automatic
Awesome, this is solved. Thanks!
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