I have a template<int d> class Monomial and a template<int d> class Polynomial. Polynomial<d> owns a std::map<Monomial<d>, double>. I would like to create a member ...

Any C++ class can be first forward declared, and defined only later in the program. Are function-local classes an exception from this rule? Please consider a simplified program: auto f() { struct ...

In C++, forward declarations introduce an incomplete type. Incomplete types can be used to declare pointers, but they cannot be used to initialize values or access members because the complete ...

I am working on a project in my spare time, and have been told to forward declare whenever possible. My project includes nlohmann::json across several files, so I thought to try and forward declare it ...

In order to hide template function definition in .cpp file, while having the forward declaration in a header file (function is used by a class template), the template has to be instantiated in order ...

When repeating the declaration of a template class with defaulted argument, I get an error: <source>:12:23: error: redefinition of default argument for 'class<template-parameter-1-2>' ...

I have this code on ADT specification of a node typedef int ElType; typedef node* Address; typedef struct node{ ElType info; Address next; } Node; Does it going to be the same if i do this? ...

I'm currently working in C++ with the elfutils library and I'm struggling with something that should be obvious. Here is a MCVE that shows my problem: file.cpp struct Elf64_Sym; #include <elf.h>...

$ g++ --version Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/4.2.1 Apple clang version ...

This is a question that has been debated many times in this forum. There is however a case that i have not seen a good way to solve. from __future__ import annotations class ClassA: pass class ...

Consider a pair of classes which represent the same thing in Python and each implements a method that converts one to the other. As an example consider transforming from cartesian to polar coordinates ...

I'm not sure if my question title is the most appropriate and I will change it happily to something clearer if I get adequate suggestion. In a C++ video whose subject is not the one here, I saw this ...

Let's suppose I want to declare structs A and B struct A{ B toB(){ return B(); } }; struct B{ A toA(){ return A(); } }; I'll get an error that type B is undefined main.cpp:2:2: error: ...

So, here I have two classes, one has the friend function definition and the other a private data member. I want to access the private data member with the friend member function but it gives me an ...

I am trying understand how I can declare, in a nim source, different procedures that call each other, as it sounds like the compiler expects all calls to come after the declaration, but the procedures ...