Don't divide by integer zero

Reason

The result is undefined and probably a crash.

Note

This also applies to %.

Example, bad

int divide(int a, int b)
{
    // BAD, should be checked (e.g., in a precondition)
    return a / b;
}

Example, good

int divide(int a, int b)
{
    // good, address via precondition (and replace with contracts once C++ gets them)
    Expects(b != 0);
    return a / b;
}

double divide(double a, double b)
{
    // good, address via using double instead
    return a / b;
}

Alternative: For critical applications that can afford some overhead, use a range-checked integer and/or floating-point type.

Enforcement

• Flag division by an integral value that could be zero