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Integer values must not be allowed to wrap, especially if they are used in any of the following ways:

• integer operands of any pointer arithmetic, including array indexing;
• the assignment expression for the declaration of a variable length array;
• the postfix expression preceding square brackets [] or the expression in square brackets [] of a subscripted designation of an element of an array object; and
• function arguments of type size_t or rsize_t (for example, an argument to a memory allocation function).
• in security-critical code

The C Standard defines arithmetic on atomic integer types as read-modify-write operations with the same representation as non-atomic integer types. As a result, wrapping of atomic unsigned integers is identical to non-atomic unsigned integers and should also be prevented or detected.

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