My header file is as follows:

```
#include <iostream>
#include <string>
#include <windows.h>
#include <math.h>

//using namespace std;

std::string StringMultiply(string Str, int Mult)
{
    std::string Return;

    for (int Index = 0; Index <= Mult; Index++)
    {
        Return += Str;
    }

    return Return;
}

```

Compiling it produces a slew of errors, most of them pertaining to the absence of a `string` datatype. Uncommenting the `using namespace std;` line fixes it, but I've been told this is bad practice in header files.