Error 1 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int apstring.h 70
Error 2 error C2556: 'std::ostream &operator <<(std::ostream &,const apstring &)' : overloaded function differs only by return type from 'int &operator <<(std::ostream &,const apstring &)' apstring.cpp 166
Error 3 error C2371: 'operator <<' : redefinition; different basic types c:\documents and settings\hooker\desktop\logbook\apstring.cpp 166
apstring.h has this typoed line in it.
ostream ;& operator << ( ostream & os, const apstring & str ); There's a rogue semicolon in there that shouldn't be.
ostream & operator << ( ostream & os, const apstring & str ); That should fix your errors. :)