objective c - How can I typecast the result of ([theEvent modifierFlags] & NSCommandKeyMask) into a BOOL? -

i have had code has been broken, , wasn't until realized isn't valid:

  bool alwaysdrawgraphic = ([theevent modifierflags] & nsalternatekeymask);    if( alwaysdrawgraphic )    {       nslog(@"hey");    } 

because result of bitwise operation & doesn't return bool.

so figured use lldb po ([theevent modifierflags] & nsalternatekeymask), error:

error: use of undeclared identifier 'nsalternatekeymask' error: 1 errors parsing expression 

so tried nslog value when have command key pressed,
nslog(@"%lu", ([theevent modifierflags] & nscommandkeymask));

xcode corrected me , let me know value unsigned long. when logs out, lu: 1048576

if command key isn't pressed, prints 0, expect

so question is, value 1048576 getting?
, how can typecast bool can re-use several times within same method?

you have check if result 0 or 1 after being masked

bool alwaysdrawgraphic = ([theevent modifierflags] & nsalternatekeymask) != 0; 

1048576 hex 0x00100000 bit position of nscommandkeymask