io_uring_cqe

pub const io_uring_cqe = extern struct {
    /// io_uring_sqe.data submission passed back
    user_data: u64,

    /// result code for this event
    res: i32,
    flags: u32,

    // Followed by 16 bytes of padding if initialized with IORING_SETUP_CQE32, doubling cqe size

    pub fn err(self: io_uring_cqe) E {
        if (self.res > -4096 and self.res < 0) {
            return @as(E, @fromBackingInt(@intCast(-self.res)));
        }
        return .SUCCESS;
    }

    // On successful completion of the provided buffers IO request, the CQE flags field
    // will have IORING_CQE_F_BUFFER set and the selected buffer ID will be indicated by
    // the upper 16-bits of the flags field.
    pub fn buffer_id(self: io_uring_cqe) !u16 {
        if (self.flags & IORING_CQE_F_BUFFER != IORING_CQE_F_BUFFER) {
            return error.NoBufferSelected;
        }
        return @as(u16, @intCast(self.flags >> IORING_CQE_BUFFER_SHIFT));
    }
}