[Proposal] Agile methods

[JustNrik]

Original proposal: dotnet/vblang#115

Basically, a method with agile keyword (or whatever keyword fits) will implicitly have .ConfigureAwait(false) on each awaited expression. Useful for async libraries where you have to put it everywhere.

[scalablecory]

You may be able to use this technique instead of putting ConfigureAwait everywhere.

[bhood-zorus]

I'd like to toss in an opinion: It's unfortunate that ConfigureAwait(true) seems to be the unwanted case in pretty much everything but front-end code, but I don't think it would be appropriate to address it at the language level. Async function signatures are already unintuitive to learn, and this proposal is effectively leaking a .NET implementation detail into the language.

I'm under the impression that it's best practice to pretty much always use ConfigureAwait(false) in libraries, so my suggestion is that this be a compiler flag/something in the project properties. The language can go untouched, and the rare functions that need ConfigureAwait(true) can explicitly say so if the project is opted-in.

[ufcpp]

@brandonhood
That's #2542.

[bhood-zorus]

@ufcpp Thanks for the link!