| @@ -161,6 +161,11 @@ async unsafe fn surface_drop_in_place<T: Drop + ?Sized>(ptr: *mut T) { |
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/// wrapped future completes by returning `Poll::Ready(())` on poll. This |
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/// is useful for constructing async destructors to guarantee this |
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/// "fuse" property |
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+// |
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+// FIXME: Consider optimizing combinators to not have to use fuse in majority |
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+// of cases, perhaps by adding `#[(rustc_)idempotent(_future)]` attribute for |
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+// async functions and blocks with the unit return type. However current layout |
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+// optimizations currently encode `None` case into the async block's discriminant. |
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struct Fuse<T> { |
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inner: Option<T>, |
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} |
| @@ -251,6 +256,12 @@ async unsafe fn either<O: IntoFuture<Output = ()>, M: IntoFuture<Output = ()>, T |
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} |
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} |
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+#[cfg(not(bootstrap))] |
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+#[lang = "async_drop_deferred_drop_in_place"] |
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+async unsafe fn deferred_drop_in_place<T>(to_drop: *mut T) { |
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+unsafe { crate::ptr::drop_in_place(to_drop) } |
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+} |
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+ |
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/// Used for noop async destructors. We don't use [`core::future::Ready`] |
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/// because it panics after its second poll, which could be potentially |
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/// bad if that would happen during the cleanup. |