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How do you install Boost on MacOS?

...st.org/users/download/#live Unpack and go into the directory:tar -xzf boost_1_50_0.tar.gz cd boost_1_50_0 Configure (and build bjam): ./bootstrap.sh --prefix=/some/dir/you/would/like/to/prefix Build: ./b2 Install:./b2 install Depending on the prefix you choose in Step 3, you might need to sudo S...
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What are the rules for calling the superclass constructor?

...: class A : public B { public: A(int a, int b, int c); private: int b_, c_; }; Then, assuming B has a constructor which takes an int, A's constructor may look like this: A::A(int a, int b, int c) : B(a), b_(b), c_(c) // initialization list { // do something } As you can see, the con...
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Iterating Over Dictionary Key Values Corresponding to List in Python

...ict (league) itself, or league.keys(): for team in league.keys(): runs_scored, runs_allowed = map(float, league[team]) You can also iterate over both the keys and the values at once by iterating over league.items(): for team, runs in league.items(): runs_scored, runs_allowed = map(float,...
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How do I pass a variable by reference?

...le type Let's try to modify the list that was passed to a method: def try_to_change_list_contents(the_list): print('got', the_list) the_list.append('four') print('changed to', the_list) outer_list = ['one', 'two', 'three'] print('before, outer_list =', outer_list) try_to_change_list_...
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Loop through properties in JavaScript object with Lodash

... var value = myObject.options[key]; } } Edit: the accepted answer (_.forOwn()) should be https://stackoverflow.com/a/21311045/528262 share | improve this answer | fol...
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How to initialize an array in one step using Ruby?

...rray = [ '1', '2', '3' ] You can also use a range: array = ('1'..'3').to_a # parentheses are required # or array = *('1'..'3') # parentheses not required, but included for clarity For arrays of whitespace-delimited strings, you can use Percent String syntax: array = %w[ 1 2 3 ] You can...
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Does Dart support enumerations?

...old approach before 1.8: class Fruit { static const APPLE = const Fruit._(0); static const BANANA = const Fruit._(1); static get values => [APPLE, BANANA]; final int value; const Fruit._(this.value); } Those static constants within the class are compile time constants, and this cl...
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Using “super” in C++

.....). You are quite right in your answer, including the chaining, I guess. ^_^ ... – paercebal Jun 10 '09 at 16:45 how ...
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Visual Studio support for new C / C++ standards?

...nt them (or analogues). A couple examples are variadic macros, long long, __pragma, __FUNCTION__, and __restrict. If there are other C99 features that you’d find useful in your work, let us know! We don’t hear much from our C users, so speak up and make yourselves heard http://connect.micros...
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Selecting multiple columns in a pandas dataframe

...ou can just return a view of only those columns by passing a list into the __getitem__ syntax (the []'s). df1 = df[['a', 'b']] Alternatively, if it matters to index them numerically and not by their name (say your code should automatically do this without knowing the names of the first two columns)...