How to reduce C++ code size?

Question

C++ / C#

Hello. I use SDL 2.0 under C++. I want to implement keystrokes on the keyboard.
There is a processInput method which I call 60 times per second. But the problem is that I check each key, and it turns out to be cumbersome, how can I simplify it?

case SDL_KEYDOWN:
      if (proccess_Event.key.keysym.sym == SDLK_A)
        aIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_B)
        bIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_C)
        cIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_D)
        dIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_E)
        eIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_F)
        fIsDown = true;
                        ...

All function

void Input::processInput()
{
  SDL_PollEvent(&proccess_Event);

  switch (proccess_Event.type)
  {
    case SDL_QUIT:
      SDL_DestroyWindow(g_window);
      SDL_Quit();
      exit(0);
      break;
    case SDL_KEYDOWN:
      if (proccess_Event.key.keysym.sym == SDLK_A)
        aIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_B)
        bIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_C)
        cIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_D)
        dIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_E)
        eIsDown = true;
      if (proccess_Event.key.keysym.sym == SDLK_F)
        fIsDown = true;
                        ...
  }
}

Thanks for the replies
PS
I found a similar example, but it's for GLFW, A HE SDL. It's all in one boolean

inline bool isKeyDown(int keyNum)
{
  return glfwGetKey(window, keyNum) == GLFW_PRESS;
}

Answer 1

Why can't you just take std::set or any other implementation of the Set data structure?
Pressed the button - added to set in O(1). They pressed the key - they removed it from the set in O (1). Need to check? Please - lookup O(1).
www.cplusplus.com/reference/set/set

Answer 2

Look at the switch construction, there will be less code.
In general, you can play around with map. Make a dictionary (key, the variable you need to make true).
And when pressed, look for map[key].
If you do not go into stl, then you can create 2 arrays, an array of keys and an array of positions. Look up the key in the array and then make bool at the same position true.

Answer 3

I'm not fluent in C++, but I would make it easier.

$aKeyCodes = [SDLK_A => 'user_name_func_for_A', SDLK_B => 'user_func_for_B', SDLK_C=> 'user_func_for_C']; //И так далее

if (array_key_exists($keyDownPress, $aKeyCodes) !== false) { // Вернет true если огонь
  return $aKeyCodes[$keyDownPress]();
else
   return false;

Answer 4

Do you really need a different click handler for each key? What problem are you solving?
If a handler for each key is not needed, then, as written above (you just need to check):

case SDL_KEYDOWN:
   bool characterPressed = proccess_Event.key.keysym.sym >= SDLK_A && proccess_Event.key.keysym.sym <= SDLK_Z;

If a very different handler is needed for each key, then only mapit.