namespace B { template <class _CharT> struct basic_ostream { basic_ostream& operator<<(basic_ostream& (*__pf)()); }; template <class _CharT> basic_ostream<_CharT>& endl(); struct S1 { template <class _CharT> friend void operator<<(basic_ostream<_CharT>& __os, const S1& __x); }; S1 setw(int __n); template <class _CharT> class S2; template <class _CharT> void operator<<(basic_ostream<_CharT>& __os, const S2<_CharT>& __x); template <class _CharT> struct S2 { template <class _Cp> friend void operator<<(basic_ostream<_Cp>& __os, const S2<_Cp>& __x); }; }