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What do the plus and minus signs mean in Objective-C next to a method?

... The difference between static and a class method: Define the method +foo in MYBaseClass and its subclass MYSubClass. NSArray* classes = @[ [MYBaseClass class], [MYSubClass class] ]; [classes makeObjectsPerformSelector: @selector(foo)]; Wouldn't work with a static method. That said, I would'a p...
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How to find the size of localStorage

...ly developing a site that will make use of HTML5's localStorage. I've read all about the size limitations for different browsers. However, I haven't seen anything on how to find out the current size of a localStorage instance. This question seems to indicate that JavaScript doesn't have a built in...
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php - get numeric index of associative array

... to find the numeric position of a key. I could loop through the array manually to find it, but is there a better way build into PHP? ...
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How to print a int64_t type in C

... hexadecimal. cppreference.com has a full listing of available macros for all types including intptr_t (PRIxPTR). There are separate macros for scanf, like SCNd64. A typical definition of PRIu16 would be "hu", so implicit string-constant concatenation happens at compile time. For your code to ...
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get current url in twig template?

...ttributes.get('_route_params')) %} The app global view variable contains all sorts of useful shortcuts, such as app.session and app.security.token.user, that reference the services you might use in a controller. share ...
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What's the best UI for entering date of birth? [closed]

...ry fast. For a not so advanced user I suggest using a datepicker. Since usually you also have advanced and non-advanced users I suggest a combination of text input and datepicker. share | improve th...
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Should __init__() call the parent class's __init__()?

... In Python, calling the super-class' __init__ is optional. If you call it, it is then also optional whether to use the super identifier, or whether to explicitly name the super class: object.__init__(self) In case of object, calling th...
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How does python numpy.where() work?

... How do they achieve internally that you are able to pass something like x > 5 into a method? The short answer is that they don't. Any sort of logical operation on a numpy array returns a boolean array. (i.e. __gt__, __lt__, etc all return boolea...
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How to remove all of the data in a table using Django

... Inside a manager: def delete_everything(self): Reporter.objects.all().delete() def drop_table(self): cursor = connection.cursor() table_name = self.model._meta.db_table sql = "DROP TABLE %s;" % (table_name, ) cursor.execute(sql) ...
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Replacing a 32-bit loop counter with 64-bit introduces crazy performance deviations with _mm_popcnt_

...AMD documents it and compilers don't expose it.) (Yes, these instructions all run on the same execution unit). This dependency doesn't just hold up the 4 popcnts from a single loop iteration. It can carry across loop iterations making it impossible for the processor to parallelize different loop...