add from_slice to VirtAddr

[Wasabi375]

Normally it's easily possible to create a VirtAddr via a reference using the from_ptr function. However this doesn't work with slices, because they are unsized.

My first idea was to simply modify from_ptr<T> to from_ptr<T: Sized?>, however that does not work because slices are wide pointers and therefor have to be cast into a narrow pointer first.

[Freax13]

My first idea was to simply modify from_ptr<T> to from_ptr<T: Sized?>, however that does not work because slices are wide pointers and therefor have to be cast into a narrow pointer first.

Is that a problem though? Can't we just cast through a thin pointer? i.e.

    pub fn from_ptr<T>(ptr: *const T) -> Self
    where
        T: ?Sized,
    {
        Self::new(ptr as *const () as u64)
    }

[josephlr]

Is that a problem though? Can't we just cast through a thin pointer? i.e.

I like this approach for adding support for T: ?Sized

[Wasabi375]

I did not think of casting to *const (). I like that solution. I updated the PR

[josephlr]

Looks good, could we add a unit test for using from_ptr with an unsized argument?

[josephlr]

Thanks!!

[Freax13]

Looks good to me, thanks!