title: What happens if you add a default case to a full case statements?
body: <p>As stated in the title, What happens if a default statement is added to a full case statement? Will this cause any issue in simulation/synthesis? If not, what is the purpose of adding this default statement to a full case?</p>
  <p>For example,</p>
  <pre><code>'''
  enum logic [1:0] {Reset, A, B, C} state, nstate;
  
  always_comb
  begin
      case(state)
          Reset:
              if(expr)
                  nstate = A;
              else
                  nstate = Reset;
          A:
              if(expr)
                  nstate = B;
              else
                  nstate = A;
          B:
              if(expr)
                  nstate = C;
              else
                  nstate = B;
          C:
              nstate = A
          
          default:
              nstate = Reset;
  '''
  </code></pre>