Function is_inbounds 

pub fn is_inbounds<T: MetaSized>(ptr: *const T) -> bool

Checks that ptr points to an allocation that can hold data of size calculated from T.

This function always returns true for ZSTs, since every pointer to a ZST is valid. For non-ZSTs, this function will return false if ptr is null or the size of the val pointed to exceeds isize::MAX. Otherwise, it will return true if and only if ptr points to allocated memory that can hold data of size calculated from T. Note that Kani does not support reasoning about pointers to unallocated memory, so if ptr does not point to allocated memory, verification will fail.