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C++ preprocessor __VA_ARGS__ number of arguments

... This is actually compiler dependent, and not supported by any standard. Here however you have a macro implementation that does the count: #define PP_NARG(...) \ PP_NARG_(__VA_ARGS__,PP_RSEQ_N()) #define PP_NARG_(...) \ ...
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MVVM in WPF - How to alert ViewModel of changes in Model… or should I?

... RaisePropertyChanged("ViewModelCopyOfSomeProperty"); } But typically this is only needed if more than one object will be making changes to the Model's data, which is not usually the case. If you ever have a case where you don't actually have a reference to your Model property to attach t...
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Complete Working Sample of the Gmail Three-Fragment Animation Scenario?

...at I'll refer to as "the Gmail three-fragment animation" scenario. Specifically, we want to start with two fragments, like this: ...
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Will the base class constructor be automatically called?

... age of customer be 2? It seems like the base class's constructor will be called no matter what. If so, why do we need to call base at the end sometimes? ...
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When would anyone use a union? Is it a remnant from the C-only days?

I have learned but don't really get unions. Every C or C++ text I go through introduces them (sometimes in passing), but they tend to give very few practical examples of why or where to use them. When would unions be useful in a modern (or even legacy) case? My only two guesses would be programming ...
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How do you do a limit query in JPQL or HQL?

...QL Parser, and it's a lot less forgiving. I think Query.setMaxResults() really is your only option. share | improve this answer | follow | ...
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How to read a single character from the user?

... except ImportError: self.impl = _GetchUnix() def __call__(self): return self.impl() class _GetchUnix: def __init__(self): import tty, sys def __call__(self): import sys, tty, termios fd = sys.stdin.fileno() old_settings = termios.tcge...
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Separation of business logic and data access in django

...de is confusing and, after a certain time, I cease to understand what is really happening. 10 Answers ...
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Use numpy array in shared memory for multiprocessing

... To add to @unutbu's (not available anymore) and @Henry Gomersall's answers. You could use shared_arr.get_lock() to synchronize access when needed: shared_arr = mp.Array(ctypes.c_double, N) # ... def f(i): # could be anything numpy accepts as an index such another numpy array with ...
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One-liner to check whether an iterator yields at least one element?

... Similarly if you need to check if the iterator is empty, one could use all(False for _ in iterator) will check if the iterator is empty. (all returns True if the iterator is empty, otherwise it stops when it sees the first False element) – KGardevoir Apr 3 ...