template<class E, class T, class A>
basic_ostream<E, T>& operator<<(
basic_ostream <E, T>& os,
const basic_string<E, T, A>& str);
The template function overloads operator<< to insert an object str of template class basic_string into the stream
os The function effectively returns os.write( str.c_str(), str.size()).
See the related sample program.