No Mutable Slice type exists.

[arielb1]

Currently, Rust has a core::raw::Slice type but no core::raw::MutSlice type - and the slice type has a data: _T. This forces people who want to get a *mut T into adding an additional (_T -> *mut T) cast - which may be undefined behaviour.

[steveklabnik]

Adding types to Rust requires an RFC at this point, feel free to make one if you want to see this added to Rust!