What is the difference between public, private, and protected inheritance in C++? All of the questions I’ve found on SO deal with specific cases. 16 s 16 class A { public: int x; protected: int y; private: int z; }; class B : public A { // x is public // y is protected // … Read more
In templates, where and why do I have to put typename and template on dependent names? What exactly are dependent names anyway? I have the following code: template <typename T, typename Tail> // Tail will be a UnionNode too. struct UnionNode : public Tail { // … template<typename U> struct inUnion { // Q: where … Read more
In C++03, an expression is either an rvalue or an lvalue. In C++11, an expression can be an: rvalue lvalue xvalue glvalue prvalue Two categories have become five categories. What are these new categories of expressions? How do these new categories relate to the existing rvalue and lvalue categories? Are the rvalue and lvalue categories … Read more
I always mess up how to use const int*, const int * const, and int const * correctly. Is there a set of rules defining what you can and cannot do? I want to know all the do’s and all don’ts in terms of assignments, passing to the functions, etc. 2 21 Read it backwards … Read more
What are undefined reference/unresolved external symbol errors? What are common causes and how to fix/prevent them? 3 37
What is a lambda expression in C++11? When would I use one? What class of problem do they solve that wasn’t possible prior to their introduction? A few examples, and use cases would be useful. 10 The problem C++ includes useful generic functions like std::for_each and std::transform, which can be very handy. Unfortunately they can … Read more
I’m coming from a Java background and have started working with objects in C++. But one thing that occurred to me is that people often use pointers to objects rather than the objects themselves, for example this declaration: Object *myObject = new Object; rather than: Object myObject; Or instead of using a function, let’s say … Read more
I just finished listening to the Software Engineering radio podcast interview with Scott Meyers regarding C++0x. Most of the new features made sense to me, and I am actually excited about C++0x now, with the exception of one. I still don’t get move semantics… What is it exactly? 1 11 I find it easiest to … Read more
What is a smart pointer and when should I use one? 1 14 UPDATE This answer is rather old, and so describes what was ‘good’ at the time, which was smart pointers provided by the Boost library. Since C++11, the standard library has provided sufficient smart pointers types, and so you should favour the use … Read more
Quote from The C++ standard library: a tutorial and handbook: The only portable way of using templates at the moment is to implement them in header files by using inline functions. Why is this? (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.) 1 17 Caveat: It … Read more
