More convenient syntax ideas?

[xwu (Xiaodi Wu)]

@Joe_Groff

try await stub(nil) ?! StubError.error ought to work. If that isn't accepted, I suspect it's a compiler bug.

The left-hand side parameter here is defined as an @autoclosure; the async/await design doesn't permit hoisting await out of an @autoclosure—I pointed this out during the original review as a pitfall since await becomes required on the right-hand side of ||, etc.

Yes, arguably a bug, but by design:

The same applies to auto closures, in order to make it explicit that the await is happening inside the closure rather than before it, it is required to await explicitly in parameter position where the auto closure is formed for the argument:

func greet(_ f: @autoclosure () async -> String) async -> String { await f() }

async let name = "Bob"
await greet(await name) // await on name is required, because autoclosure