c++ - SDL_Keycodes are too big for storage -

while searching methods of detecting multiple keys @ once in sdl 2, came across piece of code sdl 1.x:

//author: rob loach // global key buffer bool keys[256];  while(sdl_pollevent(&mainevent)) {    if(mainevent.type == sdl_keydown)    {        keys[mainevent.key.keysym.sym] = true;    }    else if(mainevent.type == sdl_keyup)    {        keys[mainevent.key.keysym.sym] = false;    } } 

i tried implementing in sdl2 , std::array<bool, 256>, had segmentation fault: 11 button.

that's when looked @ this: https://wiki.libsdl.org/sdlkeycodelookup.

most of 'special' keys including arrow, function, symbols, , on have decimal representations in billions.

even simple code printf("%d\n", e.key.keysym.sym); on, button gives:

1073741906 segmentation fault: 11 

i on mac, if makes difference error codes.

so, solutions there in sdl 2?

first of all, bools don't default in c++, need initialize them. fact appear true they're byte in size. means have size between 0 , 255 inclusive. 0 mean false 255 / 256 chance of true.

---

as solution, define std::map :

std::map<sdlkey, bool> keymap; 

an std::map empty, need check items exists when try up.

bool iskeydown(sdlkey key) {     // element     auto = keymap.find(key);      if (it == keymap.end())         // no element found, means key hasn't been pressed         return false;      // 'it' iterator, use * return value     return it->second;  } 

when try set item, automtically created if doesn't exists :

bool setiskeydown(sdlkey key, bool isdown) {     keymap[key] = isdown } 

so fact std::map empty means don't need fill it. can if want to, it's not required array.