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When would anyone use a union? Is it a remnant from the C-only days?
I have learned but don't really get unions. Every C or C++ text I go through introduces them (sometimes in passing), but they tend to give very few practical examples of why or where to use them. When would unions be useful in a modern (or even legacy) case? My only two guesses would be programming ...
How do I concatenate or merge arrays in Swift?
...ith Sequence's flatMap(_:) method
Swift provides a flatMap(_:) method for all types that conform to Sequence protocol (including Array). flatMap(_:) has the following declaration:
Returns an array containing the concatenated results of calling the given transformation with each element of this ...
JRE 1.7 - java version - returns: java/lang/NoClassDefFoundError: java/lang/Object
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This problem stems from an improper Java installation.
Possibility 1
NOTE: This scenario only applies to Java 8 and prior. Beginning with Java 9, the JRE is structured differently. rt.jar and friends no longer exist, and Pack200 is no longer used.
The Java standa...
How to create a video from images with FFmpeg?
...pix_fmt yuv420p out.ogg
Your images should of course be sorted alphabetically, typically as:
0001-first-thing.jpg
0002-second-thing.jpg
0003-and-third.jpg
and so on.
I would also first ensure that all images to be used have the same aspect ratio, possibly by cropping them with imagemagick or n...
What is the difference between ManualResetEvent and AutoResetEvent in .NET?
...or. The ManualResetEvent is the door, which needs to be closed (reset) manually. The AutoResetEvent is a tollbooth, allowing one car to go by and automatically closing before the next one can get through.
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How to calculate the difference between two dates using PHP?
...ferred way of doing this is like described by jurka below. My code is generally only recommended if you don't have PHP 5.3 or better.
Several people in the comments have pointed out that the code above is only an approximation. I still believe that for most purposes that's fine, since the usage of...
What is the most effective way for float and double comparison?
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Be extremely careful using any of the other suggestions. It all depends on context.
I have spent a long time tracing a bugs in a system that presumed a==b if |a-b|<epsilon. The underlying problems were:
The implicit presumption in an algorithm that if a==b and b==c then a==c.
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What is the purpose of the word 'self'?
...way that makes the instance to which the method belongs be passed automatically, but not received automatically: the first parameter of methods is the instance the method is called on. That makes methods entirely the same as functions, and leaves the actual name to use up to you (although self is th...
How to add a WiX custom action that happens only on uninstall (via MSI)?
I would like to modify an MSI installer (created through WiX ) to delete an entire directory on uninstall.
6 Answers
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Getters \ setters for dummies
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Isnt it really painful that MS does not support JS correctly and they do not make their silverlight run everywhere, so I have to program everything twice, one for SL and one for rest of the world :)
– Akash Kava
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