Compiler error: does not name a type

I'm new to c++ and I usually can pick through errors and figure out what's wrong but I'm stumped.

I'm getting an error saying "line|10|error: 'string' in class 'mine' does not name a type"

Here is mine.h:

#ifndef MINE_H
#define MINE_H
#include <iostream>
#include <string>

using namespace std;

class mine
{

public:
mine();
string getName();

};

#endif // MINE_H

Here is mine.cpp:

#include "mine.h"
#include <iostream>
#include <string>

using namespace std;
mine::mine()
{
    //ctor
}

mine::string getName()
{

}