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Hidden Features of Java

...en I first discovered it, never heard of it before. ThreadLocals are typically not so widely known as a way to store per-thread state. Since JDK 1.5 Java has had extremely well implemented and robust concurrency tools beyond just locks, they live in java.util.concurrent and a specifically interest...
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How to loop through all enum values in C#? [duplicate]

...rough an extra iterator (.Cast<Foos>), and (2) you don't need to box all the values and unbox them again. Şafak's cast will remain valid as long as they don't change the array type returned to some other type (like object[]). But we can be completely sure they won't because (a) it would lose ...
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symbolic link: find all files that link to this file

Hallo all, I need to do this in linux: 3 Answers 3 ...
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Chmod recursively

...have an archive, which is archived by someone else, and I want to automatically, after I download it, to change a branch of the file system within the extracted files to gain read access. (I can't change how archive is created). ...
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How does the keyword “use” work in PHP and can I import classes with it?

...t;baz; } } class Cls { use Stuff; // import traits like this } $foo = new Cls; echo $foo->bar(); // spits out 'baz' share | improve this answer | follow ...
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Initializing a struct to 0

... The first is easiest(involves less typing), and it is guaranteed to work, all members will be set to 0[Ref 1]. The second is more readable. The choice depends on user preference or the one which your coding standard mandates. [Ref 1] Reference C99 Standard 6.7.8.21: If there are fewe...
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How to assign colors to categorical variables in ggplot2 that have stable mapping?

...maintain consistent color schemes across multiple data frames that are not all obtained by subsetting a single large data frame. Managing the factors levels in multiple data frames can become tedious if they are being pulled from separate files and not all factor levels appear in each file. One way...
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Can I mix Swift with C++? Like the Objective-C .mm files

... No. When you switch from .m to .mm you are actually switching from Objective-C to a different language (which has many subtle differences) called Objective-C++. So you're not really using C++; you're using Objective-C++ which accepts most C++ as input (in the same way tha...
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Why can I throw null in Java? [duplicate]

...way makes it a bit more obvious as to why this works: try { Exception foo = null; if(false) { foo = new FileNotFoundException(); } // Oops, forgot to set foo for the true case.. throw foo; } catch (Exception e){ System.out.println(e instanceof NullPointerException); ...
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How can I iterate over an enum?

... Two = 9, Three = 4, Last }; This illustrates that an enum is not really meant to iterate through. The typical way to deal with an enum is to use it in a switch statement. switch ( foo ) { case One: // .. break; case Two: // intentional fall-through case Three: ...