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Is there a Python equivalent of the C# null-coalescing operator?
In C# there's a null-coalescing operator (written as ?? ) that allows for easy (short) null checking during assignment:
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Qt: can't find -lGL error
I just reinstalled QtCreator, created new project ( Qt Application ) an got this after compilation:
8 Answers
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__proto__ VS. prototype in JavaScript
...x = x;
this.y = y;
}
var myPoint = new Point();
// the following are all true
myPoint.__proto__ == Point.prototype
myPoint.__proto__.__proto__ == Object.prototype
myPoint instanceof Point;
myPoint instanceof Object;
Here Point is a constructor function, it builds an object (data structure) p...
Convert a String In C++ To Upper Case
...orm extremely badly with g++ 5.2 -O3, and Boost 1.58 (like 30x worse than calling glibc's toupper in a loop.) There's a dynamic_cast of the locale that doesn't get hoisted out of the per-char loop. See my answer. On the plus side, this may be properly UTF-8 aware, but the slowdown doesn't come fr...
How can I check if a Perl array contains a particular value?
...For the record, this code still does iterate through the array. The map{} call simply makes that iteration very easy to type.
– Kenny Wyland
Mar 3 '12 at 23:09
3
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Simple insecure two-way data “obfuscation”?
...e to figure out your keys by just assuming that you used this code as-is! All you have to do is change some of the numbers (must be <= 255) in the Key and Vector arrays (I left one invalid value in the Vector array to make sure you do this...). You can use https://www.random.org/bytes/ to gener...
What is the difference between AF_INET and PF_INET in socket programming?
... to do is to use AF_INET in your
struct sockaddr_in and PF_INET in your call to socket(). But
practically speaking, you can use AF_INET everywhere. And, since
that's what W. Richard Stevens does in his book, that's what I'll do
here.
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What is the _snowman param in Ruby on Rails 3 forms for?
...net Explorer (5, 6, 7 and 8) to encode its parameters as unicode.
Specifically, this bug can be triggered if the user switches the browser's encoding to Latin-1. To understand why a user would decide to do something seemingly so crazy, check out this google search. Once the user has put the web-sit...
How to write a large buffer into a binary file in C++, fast?
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Try the following, in order:
Smaller buffer size. Writing ~2 MiB at a time might be a good start. On my last laptop, ~512 KiB was the sweet spot, but I haven't tested on my SSD yet.
Note: I've noticed that very large buffers tend to decrease performance. ...
In-memory size of a Python structure
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Yep. The "4 higher" actually mostly look like "rounding up to a multiple of 8" which I believe is correct for the way malloc behaves here. No idea why decimal gets so distorted (with pympler on 2.6, too).
– Alex Martelli
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