what does it use two "!!"

Ben Wu crayben at yahoo.cn
Mon Apr 1 03:10:46 EDT 2013


Dear All:
1> I found some placeuse two "!!", what's means 
    if(button->gpio != INVALID_GPIO)
        state = !!((gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low);
    else
        state = !!button->adc_state;

2> is there some MSN group to study linux kernel or discuss it ?

Thanks and Best Regards

Ben Wu

MSN:crayben at yahoo.cn

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20130401/59223f6f/attachment.html 


More information about the Kernelnewbies mailing list