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You can't change the async/await rules of Rust anymore. I get that. But if it started like I described from the beginning I don't see why that wouldn't work. It's just a question of syntax. Someone adding a blocking call 5 layers down wouldn't be any different than someone adding an "await foo()" right now. Code would still compile fine. As long as everything follows the same rules. Can't mix them obviously.

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> wouldn't be any different than someone adding an "await foo()" right now

It would. `.await` works only inside `async` context. So if the method wasn't async at the top level, then adding `.await` somewhere down the call chain would force changing all the signatures up to now become `async`.

So you cannot just freely add `.await` at random places that don't expect it. Which is sometimes a blessing and sometimes a curse. Definitely when trying to hack a quick and dirty prototype this is a slowdown. But it is really good when you aim for low latency and predictability.

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