epoll_data alignement problem #3879
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Stargateur
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Reading more deeply I may have miss interpreted the alignment 1, it's only work for field of size 1 like |
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How about using |
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rust-lang/rust#46043 introduce a problem concerning
epoll_data. I didn't find a way to assume it safe for me to take a reference ofu64orevents.My crate define a struct:
This allow me to copy layout from
libc::epoll_eventon every os very easily without the need to handle every os layout myself but this disallow me to know when the alignment of the struct is 1.For
eventsis not a big deal for me cause I just copy according to the linked issue the compiler will handle it correctly but my use ofu64can't allow copy.Is there a rust cfg like
cfg_attr(aligned_is(1))or something like that ? With this I could assume is safe to take using unsafe and if aligned is not 1 I can use a code that doesn't use unsafe letting the compiler check the safety for me.Without something like this is become very hard for me to use
libc::epoll_event. I need to assume that the packed structure is 1 aligned. Of course I expect every OS that use a packedlibc::epoll_eventshould be#[repr(packed(1))]so it should not be a big deal but nothing prevent an OS to do that.Beta Was this translation helpful? Give feedback.
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