I'm a fresh man in C++.

I write this simple program to practice Overlaoding.

This is my code:

#include <iostream>
#include <string>
using namespace std;

class sex_t
{
private:
    char __sex__;
public:
    sex_t(char sex_v = 'M'):__sex__(sex_v)
    {
        if (sex_v != 'M' && sex_v != 'F')
        {
            cerr << "Sex type error!" << sex_v << endl;
            __sex__ = 'M';
        }
    }

    const ostream& operator << (const ostream& stream)
    {
        if (__sex__ == 'M')
            cout << "Male";
        else
            cout << "Female";
        return stream;
    }
};

int main(int argc, char *argv[])
{
    sex_t me('M');
    cout << me << endl;
    return 0;
}

When I compiler it, It print a lots of error message:

The error message was in a mess.

It's too hard for me to found useful message

sex.cpp: ???‘int main(int, char**)’?:
sex.cpp:32:10: ??: ‘operator<<’?‘std::cout << me’?????
sex.cpp:32:10: ??: ???:
/usr/include/c++/4.6/ostream:110:7: ??: std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostre