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What is the difference between quiet NaN and signaling NaN?

...+ in this answer instead of C because it offers the convenient std::numeric_limits::quiet_NaN and std::numeric_limits::signaling_NaN which I could not find in C conveniently. I could not however find a function to classify if a NaN is sNaN or qNaN, so let's just print out the NaN raw bytes: main.c...
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What does the restrict keyword mean in C++?

...h the time. Edit I also found that IBM's AIX C/C++ compiler supports the __restrict__ keyword. g++ also seems to support this as the following program compiles cleanly on g++: #include <stdio.h> int foo(int * __restrict__ a, int * __restrict__ b) { return *a + *b; } int main(void) { ...
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What is the fastest/most efficient way to find the highest set bit (msb) in an integer in C?

... GCC has: -- Built-in Function: int __builtin_clz (unsigned int x) Returns the number of leading 0-bits in X, starting at the most significant bit position. If X is 0, the result is undefined. -- Built-in Function: int __builtin_clzl (unsigned long...
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Why doesn't Python have a sign function?

...y removed and replaced by sign! Have you never implemented a class with a __cmp__ method? Have you never called cmp and specified a custom comparator function? In summary, I've found myself wanting a sign function too, but copysign with the first argument being 1 will work just fine. I disagree ...
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How do I read any request header in PHP

...instead of all headers, the quickest method is: <?php // Replace XXXXXX_XXXX with the name of the header you need in UPPERCASE (and with '-' replaced by '_') $headerStringValue = $_SERVER['HTTP_XXXXXX_XXXX']; ELSE IF: you run PHP as an Apache module or, as of PHP 5.4, using FastCGI (simple me...
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How to get the parent dir location

...bspath doesn't validate anything, so if we're already appending strings to __file__ there's no need to bother with dirname or joining or any of that. Just treat __file__ as a directory and start climbing: # climb to __file__'s parent's parent: os.path.abspath(__file__ + "/../../") That's far less...
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In Python, how do I indicate I'm overriding a method?

...an think of a better solution please post it here! def overrides(interface_class): def overrider(method): assert(method.__name__ in dir(interface_class)) return method return overrider It works as follows: class MySuperInterface(object): def my_method(self): p...
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Timer function to provide time in nano seconds using C++

...repeatedly in a loop is correct. For Linux (and BSD) you want to use clock_gettime(). #include <sys/time.h> int main() { timespec ts; // clock_gettime(CLOCK_MONOTONIC, &ts); // Works on FreeBSD clock_gettime(CLOCK_REALTIME, &ts); // Works on Linux } For windows you want t...
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PHP CURL DELETE request

...roblem, here is my solution: I created a new method: public function curl_del($path) { $url = $this->__url.$path; $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "DELETE"); $result = curl_exec($ch); $httpCode = curl_getinfo...
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What does if __name__ == “__main__”: do?

Given the following code, what does the if __name__ == "__main__": do? 33 Answers 33...