logic - how do I find if any bit of x equals 1 in C -

-

using bit-wise , logical operations, how can detect if bit of x equals 1 in c? no loops, if/else, ==, or !=

someone proposed (x & ~0) && 1, i've been looking @ hours , still don't know how (x & ~0) && 1 can detect if bit of x equals 1

!!x it.

this convert values 1, except 0 stays 0. , compilers can optimize intelligently.


Comments

Post a Comment

Popular posts from this blog

node.js - StackOverflow API not returning JSON -

-
i using node.js script gather data stackoverflow. know responses gzipped, put code in should take care of that. script follows: var request = require('request'); var zlib = require('zlib'); function getstackoverflowresponse(url, callback){ request(url, {encoding: null}, function(err, response, body){ if(response.headers['content-encoding'] == 'gzip'){ zlib.gunzip(body, function(err, dezipped) { callback(dezipped); }); } else { callback(body); } }); } var url = "https://api.stackexchange.com/docs/questions#pagesize=2&order=desc&min=2014-01-04&max=2014-02-02&sort=activity&tagged=apigee&filter=default&site=stackoverflow&run=true"; getstackoverflowresponse(url, function(questions) { console.log(questions); }); instead of getting json output, i'm getting following response: buffer 0d 0a 0d 0a 0d 0a 0d 0a 3c 21 44 4f 43 54 59 50 45 20 48...
Read more

python - Subclassed QStyledItemDelegate ignores Stylesheet -

-
i'm trying subclass qstyleditemdelegate remove focus rectangle in qcombobox . even though i'm calling base implementation of paint function , nothing else, result different. looks if parts of style-sheet influence bounding box of item taken consideration. class pstyleditemdelegate(qstyleditemdelegate): def __init__(self, *args, **kwds): super(pstyleditemdelegate, self).__init__(*args, **kwds) def paint(self, *args, **kwargs): qstyleditemdelegate.paint(*args, **kwargs) what have paint unmodified qstyleditemdelegate ? as suggested tried replacing pyside pyqt4 , works, appears bug. update pyside 1.1.2 1.2.1 result same. unfortunately switch breaks other parts of code, if there no other suggestions i'm going accept answer. edit bug tracked here
Read more

php - Laravel 4.1 to Heroku: SQLSTATE[HY000] [2002] No such file or directory -

-
i deployed laravel 4.1 app in heroku following article http://phpartisan.tumblr.com/post/71580870739/running-laravel-4-on-heroku the static html homepage loaded okay when trying log-in, getting error sqlstate[hy000] [2002] no such file or directory my local setup laravel 4.1 & mysql. i don't think there database created when deployed. do need manually? how , settings then? thanks! the problem environment might still point local. in cli, type heroku run php artisan env find out. else, might wanto run php artisan migrate --env=production set correct production environment. you might encounter issue this: php fatal error: call undefined function symfony\component\console\mb_convert_variables() in /var/www/mysite/vendor/symfony/console/symfony/component/console/application.php on line 1154 trust me, tt has nothing mb_string module post stated. laravel: call undefined function symfony\component\console\mb_convert_variables()? the problem @ e...
Read more