Valid key modifiers (possibly OR'd together).
Defined in <SDL3/SDL_keycode.h>
typedef Uint16 SDL_Keymod;
#define SDL_KMOD_NONE 0x0000u /**< no modifier is applicable. */
#define SDL_KMOD_LSHIFT 0x0001u /**< the left Shift key is down. */
#define SDL_KMOD_RSHIFT 0x0002u /**< the right Shift key is down. */
#define SDL_KMOD_LCTRL 0x0040u /**< the left Ctrl (Control) key is down. */
#define SDL_KMOD_RCTRL 0x0080u /**< the right Ctrl (Control) key is down. */
#define SDL_KMOD_LALT 0x0100u /**< the left Alt key is down. */
#define SDL_KMOD_RALT 0x0200u /**< the right Alt key is down. */
#define SDL_KMOD_LGUI 0x0400u /**< the left GUI key (often the Windows key) is down. */
#define SDL_KMOD_RGUI 0x0800u /**< the right GUI key (often the Windows key) is down. */
#define SDL_KMOD_NUM 0x1000u /**< the Num Lock key (may be located on an extended keypad) is down. */
#define SDL_KMOD_CAPS 0x2000u /**< the Caps Lock key is down. */
#define SDL_KMOD_MODE 0x4000u /**< the !AltGr key is down. */
#define SDL_KMOD_SCROLL 0x8000u /**< the Scroll Lock key is down. */
#define SDL_KMOD_CTRL (SDL_KMOD_LCTRL | SDL_KMOD_RCTRL) /**< Any Ctrl key is down. */
#define SDL_KMOD_SHIFT (SDL_KMOD_LSHIFT | SDL_KMOD_RSHIFT) /**< Any Shift key is down. */
#define SDL_KMOD_ALT (SDL_KMOD_LALT | SDL_KMOD_RALT) /**< Any Alt key is down. */
#define SDL_KMOD_GUI (SDL_KMOD_LGUI | SDL_KMOD_RGUI) /**< Any GUI key is down. */
#endif /* SDL_keycode_h_ */
This datatype is available since SDL 3.1.3.