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Are members of a C++ struct initialized to 0 by default?
I have this struct :
8 Answers
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After Installing Java JDK 7 For Mac OS X - mvn -version still shows java version 1.6.0_31
...lling Maven on a 64-bit Mac running Mac OSX 'Mavericks' save yourself some time and some hair pulling trying to get Maven installed. I was trying to follow this (which failed because the location of the java_home has changed on Mavericks:
http://maven.apache.org/download.cgi
I was pulling my hair ...
Optimise PostgreSQL for fast testing
...erformance improvements are always coming, so you're probably wasting your time if you're tuning an old version. For example, PostgreSQL 9.2 significantly improves the speed of TRUNCATE and of course adds index-only scans. Even minor releases should always be followed; see the version policy.
Don't...
How to calculate moving average without keeping the count and data-total?
...t @Muis describes is an exponentially weighted moving averge, which is sometimes appropriate but is not precisely what the OP requested. As an example, consider the behaviour you expect when most of the points are in the range 2 to 4 but one value is upwards of a million. An EWMA (here) will hold ...
Caveats of select/poll vs. epoll reactors in Twisted
...on the order of 10 or fewer), select can beat epoll in memory usage and runtime speed. Of course, for such small numbers of sockets, both mechanisms are so fast that you don't really care about this difference in the vast majority of cases.
One clarification, though. Both select and epoll scale l...
How do I discover memory usage of my application in Android?
...nterpreting whatever numbers you get is extremely low. (Pretty much every time I look at memory usage numbers with other engineers, there is always a long discussion about what they actually mean that only results in a vague conclusion.)
Note: we now have much more extensive documentation on Manag...
When should null values of Boolean be used?
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Use boolean rather than Boolean every time you can. This will avoid many NullPointerExceptions and make your code more robust.
Boolean is useful, for example
to store booleans in a collection (List, Map, etc.)
to represent a nullable boolean (coming from a nul...
pip installing in global site-packages instead of virtualenv
...a how it started. My suspicion is running multiple virtualenvs at the same time).
If none of this works, a temporary solution may be to, as Joe Holloway said,
Just run the virtualenv's pip with its full path (i.e. don't rely on searching the executable path) and you don't even need to activate ...
Why is there no Constant feature in Java?
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Every time I go from heavy C++ coding to Java, it takes me a little while to adapt to the lack of const-correctness in Java. This usage of const in C++ is much different than just declaring constant variables, if you didn't know. ...
How to get whole and decimal part of a number?
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The floor() method doesn't work for negative numbers. This works every time:
$num = 5.7;
$whole = (int) $num; // 5
$frac = $num - $whole; // .7
...also works for negatives (same code, different number):
$num = -5.7;
$whole = (int) $num; // -5
$frac = $num - $whole; // -.7
...