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error: ‘NULL’ was not declared in this scope
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Now that C++11 is more generally supported by compilers, it might be worth mentioning the nullptr keyword, which is an actual keyword and doesn't require any #includes. It's also more typesafe than NULL.
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Fastest way to get the first object from a queryset in django?
...'m pretty sure you'll even see this add LIMIT 1 to the query, and I don't know that you can do any better than this. However, internally __nonzero__ in QuerySet is implemented as try: iter(self).next() except StopIteration: return false... so it doesn't escape the exception.
–...
If strings are immutable in .NET, then why does Substring take O(n) time?
...t a win; all you've done is made your garbage collector get slower because now it has to worry about handling interior pointers.
If the substring operations people typically did on strings were completely different, then it would make sense to go with a persistent approach. If people typically had...
How to set a JavaScript breakpoint from code in Chrome?
...rs to be Chrome only at this time, but that's my primary platform anyways. Now I just need to remember to stop calling my global debugging flag "debug"...
– brichins
Sep 23 '16 at 21:48
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What's the difference between using CGFloat and float?
... to make your app 64-bit clean and try running it as such, since most Macs now have 64-bit CPUs and Snow Leopard is fully 64-bit, including the kernel and user applications. Apple's 64-bit Transition Guide for Cocoa is a useful resource.
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JPA OneToMany not deleting child
...e JPA doesn't cater for it.
In part this is because JPA doesn't actually know if it should delete something removed from the collection. In object modeling terms, this is the difference between composition and "aggregation*.
In composition, the child entity has no existence without the parent. A c...
SQL, Postgres OIDs, What are they and why are they useful?
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if you don't know what OIDs are used for then you probably don't want to be using them.
– vdegenne
Jul 9 '16 at 21:26
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How to grep a text file which contains some binary data?
...binary files are treated differently:
When searching binary data, grep now may treat non-text bytes as line
terminators. This can boost performance significantly.
So what happens now is that with binary data, all non-text bytes
(including newlines) are treated as line terminators. If you wan...
jQuery get input value after keypress
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Works, but with jquery 2.x out this is out of date now as the answer below using the on and input is the best way to do it now.
– Piotr Kula
Jul 16 '14 at 16:14
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How to duplicate virtualenv
...ext editor, you'll see something like:
Django==1.3
Fabric==1.0.1
etc...
Now, edit the line that says Django==x.x to say Django==1.3 (or whatever version you want to install in your new virtualenv).
Lastly, activate your new virtualenv, and run:
pip install -r requirements.txt
And pip will aut...