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What are C++ functors and their uses?

...42); // create an instance of the functor class int i = add42(8); // and "call" it assert(i == 50); // and it added 42 to its argument std::vector<int> in; // assume this contains a bunch of values) std::vector<int> out(in.size()); // Pass a functor to std::transform, which calls the fu...
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Why do some C# lambda expressions compile to static methods?

...l implementation most likely varies slightly): private class <Main>b__0 { public int age; public void withClosure(string s) { Console.WriteLine("My name is {0} and I am {1} years old", s, age) } } private static class <Main>b__1 { public static void withoutC...
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Detecting iOS / Android Operating system

... @feeela sometimes the feature is something like being able to install apks, which isn't possible to detect. – Daniel Lubarov Mar 7 '16 at 21:11 2 ...
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Get __name__ of calling function's module in Python

....stack()[1] mod = inspect.getmodule(frm[0]) print '[%s] %s' % (mod.__name__, msg) share | improve this answer | follow | ...
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Unique Key constraints for multiple columns in Entity Framework

... third approach may not necessarily be the best. (I like the first one actually.) I personally prefer not having any EF artifacts carried over into my entity classes. – Najeeb Nov 11 '17 at 12:45 ...
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Python dictionary: Get list of values for list of keys

...n list-comp: Build list and throw exception if key not found: map(mydict.__getitem__, mykeys) Build list with None if key not found: map(mydict.get, mykeys) Alternatively, using operator.itemgetter can return a tuple: from operator import itemgetter myvalues = itemgetter(*mykeys)(mydict) # use ...
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Can a dictionary be passed to django models on create?

...our model is called MyModel: # create instance of model m = MyModel(**data_dict) # don't forget to save to database! m.save() As for your second question, the dictionary has to be the final argument. Again, extra and extra2 should be fields in the model. m2 =MyModel(extra='hello', extra2='world'...
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pandas three-way joining multiple dataframes on columns

...SV files. Each has the first column as the (string) names of people, while all the other columns in each dataframe are attributes of that person. ...
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Do you need text/javascript specified in your tags?

...tribute is optional. Since Netscape 2, the default programming language in all browsers has been JavaScript. In XHTML, this attribute is required and unnecessary. In HTML, it is better to leave it out. The browser knows what to do. ...
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How can I use “sizeof” in a preprocessor macro?

.... Following snippets will produce no code if sizeof(someThing) equals PAGE_SIZE; otherwise they will produce a compile-time error. 1. C11 way Starting with C11 you can use static_assert (requires #include <assert.h>). Usage: static_assert(sizeof(someThing) == PAGE_SIZE, "Data structure do...