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Different types of thread-safe Sets in Java
There seems to be a lot of different implementations and ways to generate thread-safe Sets in Java.
Some examples include
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How to pass objects to functions in C++?
...ence or not.)
Passing by pointer is virtually never advised. Optional parameters are best expressed as a std::optional (boost::optional for older std libs), and aliasing is done fine by reference.
C++11's move semantics make passing and returning by value much more attractive even for complex objec...
What is the difference between active and passive FTP?
Can someone tell me what is the difference between active and passive FTP?
Which one is preferable?
5 Answers
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INNER JOIN vs LEFT JOIN performance in SQL Server
... that uses INNER JOIN on 9 tables, anyway this command takes a very long time (more than five minutes). So my folk suggested me to change INNER JOIN to LEFT JOIN because the performance of LEFT JOIN is better, despite what I know. After I changed it, the speed of query got significantly improved.
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What is the correct answer for cout
...rantees that all side effects of previous evaluations will have been performed at sequence points. There are no sequence points in between function arguments evaluation which means that argument a can be evaluated before argument std::operator<<(std::cout, a++) or after. So the result of the a...
How do I find the duplicates in a list and create another list with them?
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To remove duplicates use set(a). To print duplicates, something like:
a = [1,2,3,2,1,5,6,5,5,5]
import collections
print([item for item, count in collections.Counter(a).items() if count > 1])
## [1, 2, 5]
Note that Counter is not particularly efficient (timings) and probab...
What’s the difference between ScalaTest and Scala Specs unit test frameworks?
Both are BDD (Behavior Driven Development) capable unit test frameworks for Scala written in Scala. And Specs is built upon may also involve the ScalaTest framework. But what does Specs offer ScalaTest doesn't? What are the differences?
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Is multiplication and division using shift operators in C actually faster?
...e code sequence is. It's even possible that the processor itself has implemented the multiply instruction as a sequence of shifts & adds in microcode.
Bottom line--don't spend a lot of time worrying about this. If you mean to shift, shift. If you mean to multiply, multiply. Do what is seman...
Convert a Git folder to a submodule retrospectively?
Quite often it is the case that you're writing a project of some kind, and after a while it becomes clear that some component of the project is actually useful as a standalone component (a library, perhaps). If you've had that idea from early on, then there's a fair chance that most of that code is ...
How can I add reflection to a C++ application?
I'd like to be able to introspect a C++ class for its name, contents (i.e. members and their types) etc. I'm talking native C++ here, not managed C++, which has reflection. I realise C++ supplies some limited information using RTTI. Which additional libraries (or other techniques) could supply this ...