From Guru of the Week 2. We have the function:

string FindAddr(const list<Employee> l, string name)
{
    for( list<Employee>::const_iterator i = l.begin(); i != l.end(); i++)
    {
        if( *i == name ) // here will be compilation error
        {
            return (*i).addr;
        }
    }
    return "";
}

I added dummy Employee class to that:

class Employee
{
    string n;
public:
    string addr;

Employee(string name) : n(name) {}
Employee() {}

string name() const
{
    return n;
}

operator string()
{
    return n;
}
};

And got compilation error:

error: no match for ‘operator==’ in ‘i.std::_List_iterator<_Tp>::operator* [with _Tp = Employee]() == name’

It works only if add operator== to Employee. But, Herb Sutter wrote that:

The Employee class isn't shown, but for this to work it must either have a conversion to string or a conversion ctor taking a string.

But Employee has a conversion function and conversion constructor as well. GCC version 4.4.3. Compiled normally, g++ file.cpp without any flags.

There should be implicit conversion and it should work, why it doesn't?