Set a pointer to a new value if it is currently an old value.
void **a, void *oldval, void *newval);SDL_bool SDL_AtomicCASPtr(
|a pointer to a pointer
|the old pointer value
|the new pointer value
Returns SDL_TRUE if the pointer was set, SDL_FALSE otherwise.
Note: If you don't know what this function is for, you shouldn't use it!
This function is available since SDL 2.0.0.