Casting unsafe pointer to struct containing borrowed pointer

test.rs

struct Test<'t> {
    i: &'t int
}

unsafe fn cast<'t>(test: &'t *mut std::libc::c_void) -> &'t mut Test<'t> {
    &*(test.clone() as *mut Test<'t>)
}

pub fn main() {
    unsafe {
        let i = 1;
        let mut t = Test{i: &i};
        let ptr = std::ptr::to_mut_unsafe_ptr(&t) as *mut std::libc::c_void;
        let c = cast(&ptr);
    }
}