ii.14.4.1-unmanaged-pointers.md

II.14.4.1 Unmanaged pointers

Unmanaged pointers (*) are the traditional pointers used in languages like C and C++. There are no restrictions on their use, although, for the most part, they result in code that cannot be verified. While it is perfectly valid to mark locations that contain unmanaged pointers as though they were unsigned integers (and this is, in fact, how they are treated by the VES), it is often better to mark them as unmanaged pointers to a specific type of data. This is done by using * in a signature for a return value, local variable, or an argument, or by using a pointer type for a field or array element.

• Unmanaged pointers are not reported to the garbage collector and can be used in any way that an integer can be used.

• Verifiable code cannot dereference unmanaged pointers.

• Unverified code can pass an unmanaged pointer to a method that expects a managed pointer. This is safe only if one of the following is true:

  1. The unmanaged pointer refers to memory that is not in memory used by the CLI for storing instances of objects ("garbage-collected memory" or "managed memory").

  2. The unmanaged pointer contains the address of a field within an object.

  3. The unmanaged pointer contains the address of an element within an array.

  4. The unmanaged pointer contains the address where the element following the last element in an array would be located.