This crate is currently unsound due to spurious reads

[matthunz]

As pointed out in japaric/vcell#10, crates like this that use references to mmio are unsound.

I propose a new design that only stores raw pointers to prevent this behavior.
We could then initialize the cell using addr_of_mut to avoid any creation of references before that data is initialized.

pub struct VolatileCell<T> {
    ptr: *mut T,
}

impl<T> VolatileCell<T> {
    pub fn new(ptr: *mut T) -> Self {
        Self { ptr }
    }

    pub fn get(&self) -> T
    where
        T: Copy,
    {
        unsafe { self.ptr.read_volatile() }
    }

    pub fn get_mut(&self) -> T
    where
        T: Copy,
    {
        unsafe { self.ptr.read_volatile() }
    }
}

[phil-opp]

Thanks for reporting! We are currently working on a new interface based on raw pointers in #29. It still requires some polishing, but I hope that it will be ready soon.