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void foo(int x) {
  x = 3; /* visibleVisible only in the function. */
  /* ... */
}

Pointers behave in a similar fashion. A function may change a pointer to reference a different object, or NULL, yet that change is discarded once the function exits. Consequently, declaring a pointer as const is unnecessary.

void foo(int *x) {
  x = NULL; /* Visible only in the function. */
  /* ... */
}

Noncompliant Code Example

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void foo(int *x) {
  if (x != NULL) {
    *x = 3; /* visibleVisible outside function. */
  }
  /* ... */
}

If the function parameter is const-qualified, any attempt to modify the pointed-to value should cause the compiler to issue a diagnostic message.

void foo(const int *x) {
  if (x != NULL) {
    *x = 3; /* compilerCompiler should generate diagnostic message. */
  }
  /* ... */
}

As a result, the const violation must be resolved before the code can be compiled without a diagnostic message being issued.

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