This question’s answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. For many questions the answer seems to be found in “the standard”. However, where do we find that? Preferably online. Googling can sometimes feel futile, again especially for the C standards, since … Read more
Recently I’ve seen an example like the following: #include <iostream> class Foo { public: int bar; Foo(int num): bar(num) {}; }; int main(void) { std::cout << Foo(42).bar << std::endl; return 0; } What does this strange : bar(num) mean? It somehow seems to initialize the member variable but I’ve never seen this syntax before. It … Read more
I want to understand the external linkage and internal linkage and their difference. I also want to know the meaning of const variables internally link by default unless otherwise declared as extern. 9 Answers 9
I often find myself in a situation where I am facing multiple compilation/linker errors in a C++ project due to some bad design decisions (made by someone else 🙂 ) which lead to circular dependencies between C++ classes in different header files (can happen also in the same file). But fortunately(?) this doesn’t happen often … Read more
What is copy elision? What is (named) return value optimization? What do they imply? In what situations can they occur? What are limitations? If you were referenced to this question, you’re probably looking for the introduction. For a technical overview, see the standard reference. See common cases here. 5 Answers 5 Introduction For a technical … Read more
This question was already asked in the context of C#/.Net. Now I’d like to learn the differences between a struct and a class in C++. Please discuss the technical differences as well as reasons for choosing one or the other in OO design. I’ll start with an obvious difference: If you don’t specify public: or … Read more
Someone brought this article to my attention that claims (I’m paraphrasing) the STL term is misused to refer to the entire C++ Standard Library instead of the parts that were taken from SGI STL. (…) it refers to the “STL”, despite the fact that very few people still use the STL (which was designed at … Read more
How does the compilation and linking process work? (Note: This is meant to be an entry to Stack Overflow’s C++ FAQ. If you want to critique the idea of providing an FAQ in this form, then the posting on meta that started all this would be the place to do that. s to that question … Read more
I’m trying to understand rvalue references and move semantics of C++11. What is the difference between these examples, and which of them is going to do no vector copy? First example std::vector<int> return_vector(void) { std::vector<int> tmp {1,2,3,4,5}; return tmp; } std::vector<int> &&rval_ref = return_vector(); Second example std::vector<int>&& return_vector(void) { std::vector<int> tmp {1,2,3,4,5}; return std::move(tmp); } … Read more
C++ inherited arrays from C where they are used virtually everywhere. C++ provides abstractions that are easier to use and less error-prone (std::vector<T> since C++98 and std::array<T, n> since C++11), so the need for arrays does not arise quite as often as it does in C. However, when you read legacy code or interact with … Read more
