initialization-list

Issue: I have a weird issue that I wasn't expecting. I have a class called Answers and within the header is this: class Answer { char* aText; bool b_correct; public: Answer():aText(0){;} //default constructor } The main (testing) driver code is this: int main(void) { static const unsigned int MAX_ANSWERS = 5; Answer answers[MAX_ANSWERS]; } The (unexpected) weirdness I am getting is that there is an alloc happening, and I haven't used a new anywhere in my code yet. I'm guessing that the char* is calling this in the initialization list. I am using valgrind to test my code, and I'm getting 11

OK, member variables can be used to initialize other member variables in an initialization list (with care taken about the initialization order etc). What about member functions? To be specific, is this snippet legal according to the C++ standard? struct foo{ foo(const size_t N) : N_(N), arr_(fill_arr(N)) { //arr_ = fill_arr(N); // or should I fall back to this one? } std::vector<double> fill_arr(const size_t N){ std::vector<double> arr(N); // fill in the vector somehow return arr; } size_t N_; std::vector<double> arr_; // other stuff }; Yes, your use of member function in initialization list

struct B { int b1, b2; B(int, int); }; struct D : B { int d1, d2; // which is technically better ? D (int i, int j, int k, int l) : B(i,j), d1(k), d2(l) {} // 1st Base // or D (int i, int j, int k, int l) : d1(k), d2(l), B(i,j) {} // last Base }; Above is just pseudo code. In actual I wanted to know that does the order of calling base constructor matter ? Are there any bad behaviors (especially corner cases ) caused by any of the cases ? My question is on more technical aspect and not on coding styles. AnT The order you refer in your question is not the "order of calling base constructor". In

Consider the following (simplified) situation: class Foo { private: int evenA; int evenB; int evenSum; public: Foo(int a, int b) : evenA(a-(a%2)), evenB(b-(b%2)), evenSum(evenA+evenB) { } }; When i instanciate Foo like this: Foo foo(1,3); then evenA is 0, evenB is 2, but will evenSum be initialized to 2? I tried this on my current platform (iOS) and it seems to work, but I'm not sure whether this code is portable. Thanks for your help! This is well-defined and portable, 1 but it's potentially error-prone. Members are initialized in the order they're declared in the class body, not the order

I've a question about initialization of inherited members in constructor of derived class. Example code: class A { public: int m_int; }; class B: public A { public: B():m_int(0){} }; This code gives me the following output: In constructor 'B::B()': Line 10: error: class 'B' does not have any field named 'm_int' (see http://codepad.org/tn1weFFP ) I'm guessing why this happens? m_int should be member of B , and parent class A should already be initialized when initialization of m_int in B happens (because parent constructors run before member initialization of inherited class). Where is a

Is it possible to use the initialization list of a child class' constructor to initialize data members declared as protected in the parent class? I can't get it to work. I can work around it, but it would be nice if I didn't have to. Some sample code: class Parent { protected: std::string something; }; class Child : public Parent { private: Child() : something("Hello, World!") { } }; When I try this, the compiler tells me: "class 'Child' does not have any field named 'something'". Is something like this possible? If so, what is the syntax? Many thanks! It is not possible in the way you