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Undefined, unspecified and implementation-defined behavior
What is undefined behavior in C and C++? What about unspecified behavior and implementation-defined behavior? What is the difference between them?
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Is it safe to check floating point values for equality to 0?
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It is safe to expect that the comparison will return true if and only if the double variable has a value of exactly 0.0 (which in your original code snippet is, of course, the case). This is consistent with the semantics of the == operator. a == b means "a is equal to b".
It is not sa...
Does ARC support dispatch queues?
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The short answer: YES, ARC retains and releases dispatch queues.
And now for the long answer…
If your deployment target is lower than iOS 6.0 or Mac OS X 10.8
You need to use dispatch_retain and dispatch_release on your queue. ARC does not manage ...
What causes and what are the differences between NoClassDefFoundError and ClassNotFoundException?
What is the difference between NoClassDefFoundError and ClassNotFoundException ?
15 Answers
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Under what circumstances are linked lists useful?
... with a single CAS (+retries).
In a modern GC-d environment - such as Java and .NET - the ABA problem can easily be avoided.
Just wrap items you add in freshly created nodes and do not reuse those nodes - let the GC do its work.
The page on the ABA problem also provides the implementation of a lock...
What is the best Distributed Brute Force countermeasure?
...t is no secret that I am implementing an auth+auth system for CodeIgniter, and so far I'm winning (so to speak). But I've run into a pretty non-trivial challenge (one that most auth libraries miss entirely, but I insist on handling it properly): how to deal intelligently with large-scale, distribut...
ETag vs Header Expires
...d around but haven't been able to figure out if I should use both an ETag and an Expires Header or one or the other.
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How do I check if a column is empty or null in MySQL?
...e_col = ' ' (one space inserted in the string) then it works on both MySQL and Oracle, see answer of "onedaywhen". some_col = '' doesn't work on Oracle as empty strings mean NULL there.
– Johanna
May 18 '15 at 14:07
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What does ||= (or-equals) mean in Ruby?
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This question has been discussed so often on the Ruby mailing-lists and Ruby blogs that there are now even threads on the Ruby mailing-list whose only purpose is to collect links to all the other threads on the Ruby mailing-list that discuss this issue.
Here's one: The definitive list of ||= ...
How to use SVN, Branch? Tag? Trunk?
I was googling around a little bit and couldn't find a good "beginners" guide to SVN , not in the meaning of "how do I use the commands" rather; How do I control my source code?
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