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How do you round a floating point number in Perl?

.... For rounding to a certain number of digits, sprintf() or printf() is usually the easiest route. printf("%.3f", 3.1415926535); # prints 3.142 The POSIX module (part of the standard Perl distribution) implements ceil(), floor(), and a number of other mathematical and trigonometric func...
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Origin null is not allowed by Access-Control-Allow-Origin

...equest header Origin: null My PHP response header (Note that 'null' is a string). HTTP_REFERER allow cross-origin from a remote server to another. header('Access-Control-Allow-Origin: '.(trim($_SERVER['HTTP_REFERER'],'/')?:'null'),true); header('Access-Control-Allow-Credentials:true',true); I ...
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Time complexity of Euclid's Algorithm

... The base is the golden ratio obviously. Why? Because it takes exactly one extra step to compute nod(13,8) vs nod(8,5). For a fixed x if y<x the worst case performance is x=fib(n+1), y=fib(n). Here y depends on x, so we can look at x only. – Stepan Jul 27 '1...
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PHP abstract properties

...get_class($this) . ' must have a $tablename'); } } To enforce this for all derived classes of Foo_Abstract you would have to make Foo_Abstract's constructor final, preventing overriding. You could declare an abstract getter instead: abstract class Foo_Abstract { abstract public function get_...
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What's the difference between “static” and “static inline” function?

... to think that static should be used in translation units and benefit from extra check compiler does to find unused functions. And static inline should be used in header files to provide functions that can be in-lined (due to absence of external linkage) without issuing warnings. Unfortunately I ca...
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Cast Int to enum in Java

... 0 or 1, i.e. a valid ordinal for that enum. Note that in Java enums actually are classes (and enum values thus are objects) and thus you can't cast an int or even Integer to an enum. share | impr...
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Targeting .NET Framework 4.5 via Visual Studio 2010

Today I installed the .NET Framework 4.5 on my machine expecting to be able to use it from Visual Studio 2010, since it's just a minor update that should't pose problems for Visual Studio 2010. Unfortunately I am not, even manually removing certain 4.0 and adding the corresponding 4.5 assemblies r...
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Programmatically get the cache line size?

All platforms welcome, please specify the platform for your answer. 8 Answers 8 ...
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How to get a cross-origin resource sharing (CORS) post request working

... I finally stumbled upon this link "A CORS POST request works from plain javascript, but why not with jQuery?" that notes that jQuery 1.5.1 adds the Access-Control-Request-Headers: x-requested-with header to all CORS requests....
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What is the Python equivalent of static variables inside a function?

... there is only one instance of foo - this one function. all invocations access the same variable. – Claudiu Nov 10 '08 at 23:49 124 ...