Avoid Pin by using a trait object suffix for Request #3
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eddyb
reviewed
Aug 25, 2020
| where | ||
| R: ?Sized + private::Response, | ||
| { | ||
| marker: PhantomData<&'a ()>, |
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I was worried about this not being invariant, but... &mut Request<'a> is invariant over 'a because of the &mut, as it's basically a &mut (TypeId, Option<&'a T>) for some unknown T, so it has to be invariant to avoid allowing writing in a shorter lifetime.
eddyb
reviewed
Aug 25, 2020
src/lib.rs
Outdated
| _marker: PhantomData, | ||
| }, | ||
| value: None, | ||
| impl<T: 'static> Request<'_, Option<T>> { |
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I wonder if you'd maybe want to make this Request<'static, Option<T>>?
|
So I came up with a way to write |
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This simplifies the callsites significantly, as the parameter type is now a simpler
&mut Request<'a>type, and reduces the amount of unsafe code which is necessary.