No, it's not a function or operator. Bitsum = A sum of bits.
PHP Code:
new what_ever_you_want_to_name_this_variable
// Set whether or not they are alive:
if( is_user_alive(id) )
{
what_ever_you_want_to_name_this_variable |= (1<<id)
}
else
{
what_ever_you_want_to_name_this_variable &= ~(1<<id)
}
// Then use the following to check and see if they are alive:
if (what_ever_you_want_to_name_this_variable & (1<<id))
{
// User is alive.
}
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