# V3518\. AUTOSAR\. A switch\-expression should not have Boolean type\. Consider using of 'if\-else' construct\.

This diagnostic rule is based on the software development guidelines developed by [AUTOSAR](https://www.autosar.org/) \(AUTomotive Open System ARchitecture\)\.

A Boolean value can be cast to an integer and, therefore, can be used as a control variable in a 'switch' statement\. However, it is preferable to use an 'if\-else' construct in such cases as it conveys the developer's intentions in a clearer and more explicit way\.

Original code: 

```cpp
int foo(unsigned a, unsigned b)
{
  while (a != 0 && b != 0)
  {
    switch (a > b) // <=
    {
    case 0:
      a -= b;
      break;
    default:
      b -= a;
      break;
    }
  }
  return a;
}
```

Better version:

```cpp
int foo(unsigned a, unsigned b)
{
  while (a != 0 && b != 0)
  {
    if (a > b)
    {
      b -= a;
    }
    else
    {
      a -= b;
    }
  }
  return a;
}
```