I am messing around with game states in my game. Currently i have it working like below

class GameState
{
  virtual void init();
  virtual void deinit();
  virtual void draw();
  virtual void update();
};

then for each of my game states i derive a class from this base class. Then when i want to transition to a new game state...a push this new game state onto a stack. then in each loop of my game i do

game_state_stack.get_last_state().update();
game_state_stack.get_last_state().draw();

the problem i have is this. Lets say i am in a game state of GAME_STATE_PLAYING and i want to open an options screen that overlaps on the playing screen (and pauses the playing screen). So i want to push a new state called GAME_STATE_OPTIONS onto the stack. This is working fine except for the fact that i want to options screen to overlay (right work) on top of the playing screen. This would require me to redraw not just the top state in the stack but some or all of the ones below it. so then i think i will just loop through the stack and draw ALL states but only update the top state in the stack. This works but seems too much unnessary drawing. Because if i start the game with the MAIN_MENU state then user clicks on start game so we push on the GAME_STATE_PLAYING then the user opens options so we push on GAME_STATE_OPTIONS. So if we draw the whole stack then we are unneccessarily (sp?) drawing the main menu. What should I do ?

actuaqlly, i dont like this option of leaving it up to the state to draw the parent...
i think, its better information hiding, if every state has something like "doPassiveUpdate()" where in your example it can draw itself but doesnt react to input and after that, the option screen is to be drawn

the problem i am trying to avoid with the whole enum thing is HUGE if/else code blocks or HUGE switch statements to deal with all the game states.

the things i am working on now are sub-states of one of the main game states. example: i have a state GAME_PLAYING to represent the main playing portion of the game. The game is turn based to within this GAME_PLAYING state there are several sub-states such as WAITING_TO_PICK_UNIT, PICK_UNIT_ACTION, CHOOSE_TARGET, ect....

i am thinking on if i should use a switch/if/else for these of just subclass them as well and push them on the atack.

I use a similar state system and just have a flag in every state whether they desire to be rendered still. When I run through my state stack I check the flag before calling the draw() function. This way each state can control drawing functionality individually (which is required, as sometimes you want everything drawn and other times you only need the top state drawn).

Why not make an visible flag in the state, and an IsVisible accessor. Always loop through all states, and only render the ones that are visible. The one at the top of the stack will have the focus, but the rest will render afterwords, painter's style.