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What's the simplest way to test whether a number is a power of 2 in C++?
...a clever little bit hack to test that one and only one bit is set.
bool is_power_of_2(int x) {
return x > 0 && !(x & (x−1));
}
For more bit twiddling see here.
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improv...
Does SQLAlchemy have an equivalent of Django's get_or_create?
...ortcut readily available AFAIK.
You could generalize it ofcourse:
def get_or_create(session, model, defaults=None, **kwargs):
instance = session.query(model).filter_by(**kwargs).first()
if instance:
return instance, False
else:
params = dict((k, v) for k, v in kwargs.it...
Rails 4 multiple image or file upload using carrierwave
... from a file selection window using Rails 4 and CarrierWave? I have a post_controller and post_attachments model. How can I do this?
...
ASP.NET MVC partial views: input name prefixes
...n your views like this :
<%= Html.PartialFor(model => model.Child, "_AnotherViewModelControl") %>
and you will see everything is ok!
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...
Check if a variable is a string in JavaScript
...orrectly identify the value as being a string.
lodash / Underscore.js
if(_.isString(myVar))
//it's a string
else
//it's something else
jQuery
if($.type(myVar) === "string")
//it's a string
else
//it's something else
See lodash Documentation for _.isString() for more details.
See ...
Why does volatile exist?
...one. Essentially we did this:
void waitForSemaphore()
{
volatile uint16_t* semPtr = WELL_KNOWN_SEM_ADDR;/*well known address to my semaphore*/
while ((*semPtr) != IS_OK_FOR_ME_TO_PROCEED);
}
Without volatile, the optimizer sees the loop as useless (The guy never sets the value! He's nuts, g...
How do I set the UI language in vim?
...very early on, and not re-read again later. So you really do need to set LC_ALL (or more specifically LC_MESSAGES) in your environment – or on non-Unixoid systems (eg. Windows), you can pass the --cmd switch (which executes the given command first thing, as opposed to the -c option):
gvim --cmd "...
How can I get last characters of a string
...tring method .substr() combined with the .length property.
var id = "ctl03_Tabs1";
var lastFive = id.substr(id.length - 5); // => "Tabs1"
var lastChar = id.substr(id.length - 1); // => "1"
This gets the characters starting at id.length - 5 and, since the second argument for .substr() is omi...
Can't get Gulp to run: cannot find module 'gulp-util'
...t this problem try reinstalling your project's local packages:
rm -rf node_modules/
npm install
OUTDATED ANSWER
You also need to install gulp-util:
npm install gulp-util --save-dev
From gulp docs- getting started (3.5):
Install gulp and gulp-util in your project devDependencies
...
PHP server on local machine?
...o work.)
You could also add a simple Router
<?php
// router.php
if (preg_match('/\.(?:png|jpg|jpeg|gif)$/', $_SERVER["REQUEST_URI"])) {
return false; // serve the requested resource as-is.
} else {
require_once('resolver.php');
}
?>
And then run the command
php -S 127.0.0.1:8000 r...