Hi, in cln/string.h it says: -------------------- namespace cln { struct cl_string; ^^^^ .... private: // Friend declarations. They are for the compiler. Just ignore them. friend class cl_string; ^^^ ----------------------- and the meticulous MSVC-compiler gives this a warning: warning C4099: "cln::cl_string": Geben Sie den zuerst unter Verwendung von "struct" und jetzt unter Verwendung von "class" gesehenen Namen ein meaning that we should decide whether cl_string is a class or a struct. Is there any interest in eliminating this kind of warning? Then I could put together a list. Greetings, Jan