QA·C Help - 0490

	0490	Relational operator used to compare two pointers.

Pointers		REFERENCE - ISO:C90-6.3.8 Relational Operators

A relational operator is being used to compare two pointers.

Two pointers can only be compared with a relational operator when:

both operands are pointers to qualified or unqualified versions of compatible object types ; or
both operands are pointers to qualified or unqualified versions of compatible incomplete types

If the objects pointed to are not members of the same struct, array or union object, the result is undefined.

For example:


/*PRQA S 2213,3196,3408,3447 ++*/

extern unsigned int  * pui1;
extern unsigned int  * pui2;
extern unsigned char * puc1;
extern int             a;
extern int             b;

extern void foo(void)
{
    if (pui1 > puc1) { }          /* Message 0490 + 0513 - Constraint Error */

    if (pui1 > pui2) { }          /* Message 0490                           */

    if (&a < &b) { }              /* Message 0490 - Undefined behaviour     */
}

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