How can I set up a map with string as key and ostream as value?

I am trying to use the `map` container in C++ in the following way: The Key is a `string` and the value is an object of type `ofstream`. My code looks as follows: ``` #include <string> #include <iostream> #include <map> #include <fstream> using namespace std; int main() { // typedef map<string, int> mapType2; // map<string, int> foo; typedef map<string, ofstream> mapType; map<string, ofstream> fooMap; ofstream foo1; ofstream foo2; fooMap["file1"] = foo1; fooMap["file2"] = foo2; mapType::iterator iter = fooMap.begin(); cout<< "Key = " <<iter->first; } ``` However, when I try to compile the above code, I get the following error: ``` C:/Dev-Cpp/bin/../lib/gcc/mingw32/3.4.2/../../../../include/c++/3.4.2/bits/ios_base.h: In member function `std::basic_ios<char, std::char_traits<char> >& std::basic_ios<char, std::char_traits<char> >::operator=(const std::basic_ios<char, std::char_traits<char> >&)': C:/Dev-Cpp/bin/../lib/gcc/mingw32/3.4.2/../../../../include/c++/3.4.2/bits/ios_base.h:741: error: `std::ios_base& std::ios_base::operator=(const std::ios_base&)' is private hash.cpp:88: error: within this context ``` What is going wrong? If this cannot be done using `map`, is there some other way to create such key:value pair? Note: If I test my code with `map<string, int> foo;` it works fine.