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int globI;
double globD;

struct S {
  int i;
  
  S() : i(globI++) {}
};

struct T : S {
  double d;
  
  T() : S(), d(globD++) {}
};

Noncompliant Code Example (Pointer Arithmetic)

In this noncompliant code example, f() accepts an array of S objects as its first parameter. However, main() passes an array of T objects as the first argument to f(), which results in undefined behavior due to the pointer arithmetic used within the for loop.

#include <iostream>
 
// ... definitions for S, T, globI, globD ...

void f(const S *someSes, std::size_t count) { 
  for (const S *end = someSes + count; someSes != end; ++someSes) {
    std::cout << someSes->i << std::endl;
  }
}

int main() {
  T test[5];
  f(test, 5);
}

This example would still be noncompliant if the for loop had instead been written to use array subscripting, as in the following:

Noncompliant Code Example (Array Subscripting)

In this noncompliant code example, the for loop uses array subscripting. Since arry subscripts are computed using pointer arithmetic, this code also results in undefined behavior.

#include <iostream>
 
// ... definitions for S, T, globI, globD ...

void f(const S *someSes, std::size_t count) { 
  

for (std::size_t i = 0; i < count; ++i) {
    std::cout << someSes[i].i << std::endl;
  }
}

int main() {
  T test[5];
  f(test, 5);
}

Compliant Solution (Array)

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