declaring a friend function in the global namespace that returns a template class...

std::function as a friend of the class...

friend member function can't access private member data...

C++ create a friend of a function?...

Global namespace friend class cannot access private member of named namespace class...

How to pass objects as arguments?...

How to overload == operator without making it a friend function?...

C++ : operator<< fails to compile...

Class template explicit instantiation declaration...

Namespace's class's friend that is not declared and defined in the namespace...

c++ derived class accessing base class' friend operators...

ADL and friend functions of templated types...

restriction on friend function...

template friend functions of template class...

C++ Accessing an element of a private array from a friend function (operator <<)...

Problem compiling a template friend example from Stroustrup's C++...

Syntax for C++ operator overloading in a class...

where should friend functions be written?...

How can I use static members in friend functions without prefixing [class name]::...

C++ declaration of template parameter shadows template parameter error...

Linker Error when calling operator<<, how to fix this?...

Hidden friends: declarations and definitions...

c++ definition inheritance scheme...

C++ friend template that use SFINAE...

Overloading operator "<<" in C++ with template-dependent type...

C++: Making a function friend of multiple classes?...

Difference of C++17 and C++20 in template friend function with unary and binary operators...

vect.hpp:13:33: error: declaration of ‘operator<<’ as non-function...

C++ friend function with a template argument enable_if...

Friend, private function, template alias, and decltype... is clang correct in rejecting this?...