Yeah it's a good idea to post the error:
If we ignore that you called a function for a moment we can boil your code down to this
In function 'int main()':
Line 16: error: no match for 'operator<<' in 'std::operator<< [with _Traits = std::char_traits<char>](((std::basic_ostream<char, std::char_traits<char> >&)(& std::cout)), ((const char*)"2nd ")) << A_print()'
compilation terminated due to -Wfatal-errors.
cout can't exactly print itself; and you don't return a value from A_print() to display anyway. There is a way to make this syntactically correct. Break it up.
cout << "2nd " << cout << "A_print" << endl << endl;
cout << "2nd ";
cout << endl;