S3458 — Empty "case" clauses that fall through to the "default" should be omitted

Why is this an issue?

Empty case clauses that fall through to the default are useless. Whether or not such a case is present, the default clause will be invoked. Such cases simply clutter the code, and should be removed.

Noncompliant code example

switch(ch)
{
  case 'a' :
    HandleA();
    break;
  case 'b' :
    HandleB();
    break;
  case 'c' :  // Noncompliant
  default:
    HandleTheRest();
    break;
}

Compliant solution

switch(ch)
{
  case 'a' :
    HandleA();
    break;
  case 'b' :
    HandleB();
    break;
  default:
    HandleTheRest();
    break;
}