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What are rvalues, lvalues, xvalues, glvalues, and prvalues?

...e they needed? Probably not if we wish to forfeit the new features. But to allow better optimization we should probably embrace them. Quoting n3055: An lvalue (so-called, historically, because lvalues could appear on the left-hand side of an assignment expression) designates a function or an obj...
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Why does modern Perl avoid UTF-8 by default?

...????????????????????? Set your PERL_UNICODE envariable to AS. This makes all Perl scripts decode @ARGV as UTF‑8 strings, and sets the encoding of all three of stdin, stdout, and stderr to UTF‑8. Both these are global effects, not lexical ones. At the top of your source file (program, module, l...
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add column to mysql table if it does not exist

... OK this is really crude but someone's got to say it. if you are simply running a SQL script from the command line, you can give mysql the --force switch, which means keep going even if there's an error. then, just go for it. you just want...
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Semantic Issue: Property's synthesized getter follows Cocoa naming convention for returning 'owned'

... the memory management rules for declared properties, too — more specifically, for declared properties’ accessors: You take ownership of an object if you create it using a method whose name begins with “alloc”, “new”, “copy”, or “mutableCopy”. A property named newTitle, whe...
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How to create a trie in Python

... Unwind is essentially correct that there are many different ways to implement a trie; and for a large, scalable trie, nested dictionaries might become cumbersome -- or at least space inefficient. But since you're just getting started, I think...
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How to get the request parameters in Symfony 2?

... The naming is not all that intuitive: use Symfony\Component\HttpFoundation\Request; public function updateAction(Request $request) { // $_GET parameters $request->query->get('name'); // $_POST parameters $request->r...
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How to filter NSFetchedResultsController (CoreData) with UISearchDisplayController/UISearchBar

... I actually just implemented this on one of my projects (your question and the other wrong answer hinted at what to do). I tried Sergio's answer but had exception issues when actually running on a device. Yes you create two fetch ...
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How do I detect unsigned integer multiply overflow?

I was writing a program in C++ to find all solutions of a b = c , where a , b and c together use all the digits 0-9 exactly once. The program looped over values of a and b , and it ran a digit-counting routine each time on a , b and ab to check if the digits condition was satisfied. ...
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Getting distance between two points based on latitude/longitude

...just on answering the specific bug OP ran into. It's because in Python, all the trig functions use radians, not degrees. You can either convert the numbers manually to radians, or use the radians function from the math module: from math import sin, cos, sqrt, atan2, radians # approximate radiu...
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Getter and Setter?

... That's not really setter and getter. Typically I need for each property different implementation of getter! – sumid Feb 16 '13 at 0:59 ...