Forward declaration of std::wstring

Question

// This is a header file.

class MyClass; // It can be forward declared because the function uses reference.
// However, how can I do forward declaraion about std::wstri         


        

Answer 1

class std::wstring; doesn't compile. But this does:

namespace std{
class wstring;
}

However, this declaration is incompatible with the header file, which you should see if you #include after it. So it's really not safe.