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When is a C++ destructor called?
...rwise, means it uses ::operator new). Then, when you use (for example) push_back to add an item to the vector, internally the vector uses a placement new to create an item in the (previously) unused part of its memory space.
Now, what happens when/if you erase an item from the vector? It can't just ...
How do I get the last inserted ID of a MySQL table in PHP?
...ng PDO, use PDO::lastInsertId.
If you're using Mysqli, use mysqli::$insert_id.
If you're still using Mysql:
Please, don't use mysql_* functions in new code. They are no longer maintained and are officially deprecated. See the red box? Learn about prepared statements instead, and use PDO or MyS...
Why is SSE scalar sqrt(x) slower than rsqrt(x) * x?
...e multiplies in it, no divide. => Faster!
And: the full update step new_x = x + dx then reads:
x *= 3/2 - y/2 * x * x which is easy too.
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How do I declare a 2d array in C++ using new?
...nah, it's not clever at all: it's obvious.
class Matrix
{
...
size_t index( int x, int y ) const { return x + m_width * y; }
};
Given this index() function (which I'm imagining is a member of a class because it needs to know the m_width of your matrix), you can access cells within your ma...
Need to understand the usage of SemaphoreSlim
...tomdupont.net/2016/03/how-to-release-semaphore-with-using.html
I did swap _isDisposed=true and _semaphore.Release() around in its Dispose though in case it somehow got called multiple times.
Also it is important to note SemaphoreSlim is not a reentrant lock, meaning if the same thread calls WaitA...
How do I insert NULL values using PDO?
...nd this in a comment on the php docs:
bindValue(':param', null, PDO::PARAM_INT);
EDIT: P.S. You may be tempted to do this bindValue(':param', null, PDO::PARAM_NULL); but it did not work for everybody (thank you Will Shaver for reporting.)
...
Purpose of Django setting ‘SECRET_KEY’
What exactly is the point of the SECRET_KEY in django? I did a few google searches and checked out the docs ( https://docs.djangoproject.com/en/dev/ref/settings/#secret-key ), but I was looking for a more in-depth explanation of this, and why it is required.
...
Reloading the page gives wrong GET request with AngularJS HTML5 mode
...riteEngine On
Options FollowSymLinks
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /#/$1 [L]
More interesting stuff to read about html5 mode in angularjs and the configuration required per different environment https://github.com/angula...
Parse large JSON file in Nodejs
...d to hear if it works.
It does work consider the following Javascript and _.isString:
stream.pipe(JSONStream.parse('*'))
.on('data', (d) => {
console.log(typeof d);
console.log("isString: " + _.isString(d))
});
This will log objects as they come in if the stream is an array of obj...
Adding an arbitrary line to a matplotlib plot in ipython notebook
...e taken in account in the legend by adding a label argument starting with "_". Ex: plt.plot([70, 70], [100, 250], 'k-', lw=2, label="_not in legend")
– gcalmettes
Oct 29 '16 at 5:40
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