join().await vs join!()

[kuviman]

So, it seems to me that join! macro and fn join should behave similarly, but the difference between them is that fn returns a Future, while macro returns future's result (.await is included in the macro) and is only available in async context.

I think it would be better if the macro was changed to behave like the function. I think explicit .await after the macro call is actually better than implicit anyway.

[e00E]

In addition to that I'd like the documentation to state whether there is a difference between the two versions. Is there a reason to prefer one over the other?

[taiki-e]

In addition to that I'd like the documentation to state whether there is a difference between the two versions. Is there a reason to prefer one over the other?

• join! macro is variadic, it can handle any number of futures.
• join function return named type, it allows storing the returned future in a struct without unstable features.
• join function requires Rust 1.36, join! macro requires Rust 1.39.

Basically, join! macro is more flexible, but join function can help in some situations.