class

[Solved] scope resolution operator semantics [closed]

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1) What is the use of the scope resolution operator in cases like the following, when we can also define it inline? In your example, the scope resolution operator is not required when defining a method inside a class: class Box { public: double length; // Length of a box double breadth; // Breadth of … Read more

[Solved] Ruby undefined method ‘each’ for class

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Which makes absolute sense because that class indeed does not contain that method, but as I’ve been reading should ruby search the classes parents and grandparents for the method? That’s correct, but you didn’t declare any superclasses so the superclass will be Object. Which also doesn’t have an each method. If you want an enumerable … Read more

[Solved] Array of an object of a class [closed]

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It depends on how your class looks but this would be a simple example: #include <iostream> using namespace std; class MyClass { int x; public: void setX(int i) { x = i; } int getX() { return x; } }; int main() { MyClass test[4]; int i; for(i=0; i < 4; i++) test[i].setX(i); ` for(i=0; … Read more

[Solved] C++ How can I access to an inner enum class?

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P0W’s answer is correct on both counts, but in case you simply want to output the underlying value, then it may be simpler to cast rather than overload the insertion operator. using enum_type = std::underlying_type<Apple::color>::type; enum_type value = (enum_type)Apple::color::green; std::cout << value << ‘\n’; 2 solved C++ How can I access to an inner enum … Read more

[Solved] Title Name not showing and background color not changing

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Your MessageRouter is missing default processing. Add DefWindowProc as shown LRESULT CALLBACK AbstractWindow::MessageRouter ( HWND hwnd, UINT message, WPARAM w_param, LPARAM l_param ) { AbstractWindow* abstract_window = 0; if ( message == WM_NCCREATE ) { abstract_window = ( AbstractWindow* ) ( ( LPCREATESTRUCT ( l_param ) )->lpCreateParams ); SetWindowLong ( hwnd, GWL_USERDATA, long ( abstract_window … Read more

[Solved] Declare “Nullable[]” or “string[]?” for string array property that may or may not exist inside a class?

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In short: you don’t need Nullable<T> or ? in this case at all. string[] is reference type: Console.WriteLine(typeof(string[]).IsValueType); the printed output will be false. So, it can be null without any decoration. Back to your sample. You need to specify setters as well to be able deserialize the given json fragement: public class Settings { … Read more

[Solved] Having trouble implementing a nested class comparator

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You should provide inner class instance into Arrays.sort to compare points from view of parent class instance. To do it you should not create new instance in main() function, but get it from Point instance. So, in main function you should use something like this: Point pivot; … // set up pivot point here Arrays.sort(myPoints, … Read more

[Solved] Need to implement the Python itertools function “chain” in a class

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There is not (much) difference between def chain_for(*a): and def __init__(self, *a):. Hence, a very crude way to implement this can be: class chain_for: def __init__(self, *lists): self.lists = iter(lists) self.c = iter(next(self.lists)) def __iter__(self): while True: try: yield next(self.c) except StopIteration: try: self.c = iter(next(self.lists)) except StopIteration: break yield next(self.c) chain = chain_for([1, 2], … Read more

[Solved] Passing map (matrix) to class C++ [closed]

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Try using Boost.MultiArray. It allows you to create multidimensional arrays with contents of arbitrary content type. I have used it (the boost::multi_array_ref part to be more specific) and it works pretty nice. An important feature is the ability to create array views (and slices based on views). solved Passing map (matrix) to class C++ [closed]