Synopsis

Do not modify constant objects.

Enabled by default

Yes

Severity/Certainty

Low/Low

Full description

If an attempt is made to modify an object defined with a const-qualified type through use of an lvalue with non-const-qualified type, the behavior is undefined.

Coding standards

Code examples

The following code example fails the check and will give a warning:

const int **ipp;
int *ip;
const int i = 42;

void example(void) {
  ipp = &ip; /* Constraint violation */
  *ipp = &i; /* Valid */
  *ip = 0;   /* Modifies constant i (was 42) */
}

The following code example passes the check and will not give a warning about this issue:

int **ipp;
int *ip;
int i = 42;

void example(void) {
  ipp = &ip; /* Valid */
  *ipp = &i; /* Valid */
  *ip = 0; /* Valid */
}