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When to use os.name, sys.platform, or platform.system?
...specific modules are available (e.g. posix, nt, ...)
platform.system() actually runs uname and potentially several other functions to determine the system type at run time.
My suggestion:
Use os.name to check whether it's a posix-compliant system.
Use sys.platform to check whether it's a linux,...
What is the type of lambda when deduced with “auto” in C++11?
...
The type of a lambda expression is unspecified.
But they are generally mere syntactic sugar for functors. A lambda is translated directly into a functor. Anything inside the [] are turned into constructor parameters and members of the functor object, and the parameters inside () are turned ...
Java SafeVarargs annotation, does a standard or best practice exist?
...n StackOverflow about the particular issue with generics and varargs. Basically, it's when you have a variable number of arguments of a type-parameter type:
<T> void foo(T... args);
In Java, varargs are a syntactic sugar that undergoes a simple "re-writing" at compile-time: a varargs parame...
Creating JS object with Object.create(null)?
...t.create(null) doesn't inherit from anything and thus has no properties at all.
In other words: A javascript object inherits from Object by default, unless you explicitly create it with null as its prototype, like: Object.create(null).
{} would instead be equivalent to Object.create(Object.prototy...
ASP.NET MVC - Should business logic exist in controllers?
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Business logic should really be in the model. You should be aiming for fat models, skinny controllers.
For example, instead of having:
public interface IOrderService{
int CalculateTotal(Order order);
}
I would rather have:
public class Ord...
How to know if user is logged in with passport.js?
...sport.js info and samples for two days, but I'm not sure after that I did all the process of authenticating.
6 Answers
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AI2 SideBar Extension
Deutsche Version Motivation With smaller apps, the implemented functions can be triggered by a button. With larger apps, however, the available space quickly decreases and the layout becomes confusing. A side bar can help here. There are a number of implementations, but I haven't found a su...
Does the JVM prevent tail call optimizations?
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This post: Recursion or Iteration? might help.
In short, tail call optimization is hard to do in the JVM because of the security model and the need to always have a stack trace available. These requirements could in theory be supported, but it would probably require a new bytecode (see J...
PHP memory profiling
...r example, to see how much memory my data is using, and/or which function calls are allocating the most memory.
4 Answers
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How do I declare a 2d array in C++ using new?
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A dynamic 2D array is basically an array of pointers to arrays. You can initialize it using a loop, like this:
int** a = new int*[rowCount];
for(int i = 0; i < rowCount; ++i)
a[i] = new int[colCount];
The above, for colCount= 5 and rowCount =...