// Multiple level of nesting
void func() 
{
  if (...) {
    if (...) {
      ...
    } else {
      if (...) {
        ...
      } else if (...) {
        ...
      } else {
        ...
      }
    }
  ...
  }
}
// Convert if-else to if-return
void func()
{
  if (!test()) {
    handle_failure();
    return false;
  }
  // do lots of work
} 

// Multiple return in function not allowed
// Convert if-else to success/failure boolean
void func()
{
  bool success = section_1();

  if (success) {
      success = section_2();
  }

  if (success) {
      success = section_3();
  }
}

// Shorter
void func()
{
  bool success = section_1();
  success = success && section_2();
}

// Shorter
void func()
{
  bool success = section_1();
  success &= section_2();
}

// In for-loop, convert if-else to if-continue
for(...) {
  const T& element = *iter;

  if (!test(element))
      continue;
  ...
}