problem overloading + operator

[gasfusion]

I'm coding a program which calculates time values in hh:mm:ss format.
I'm reading times from a file containing 1 time string per line. After reading times, i continue reading operations on the time in the same file. operations are like this:
167+234

which basically means i take the 167th row in the file and add it with 234th.

here is what i have so far. Note the >> operator is also overloaded.

myClass operationAnswer, myArray[300]; // this is actually a dynamic array in my program.
int Index1, Index2;
char sign;
                // Assume i already read the times... Reading operations now
        while(!fin.eof() && fin >> Index1
                                >> sign
                                >> Index2) {
 if (sign == '+') 
   myAnswer = myArray[Index1] + myArray[Index2];
 else
  // do subtraction  
 

And this is my overloaded + operator

DateProcessorClass operator + (DateProcessorClass& left, DateProcessorClass& right)
{
    /* Cannot pass by reference because we'll expose private variables */
    int resultSec, resultMin, resultHour;
    int tempMinutes, tempHours;
 
    resultSec = left.getSeconds() + right.getSeconds();
    tempMinutes = left.getMinutes();
    if (resultSec > 60)
    {
        resultSec = resultSec - 60;
        tempMinutes = left.getMinutes() + 1;
    }
    resultMin = tempMinutes + right.getMinutes();
    tempHours = left.getHours();
    if (resultMin > 60)
    {
        resultMin = resultMin - 60;
        tempHours = left.getHours() + 1;
    }
    resultHour = tempHours + right.getHours();
    return DateProcessorClass(resultHour,resultMin,resultSec);
}
 

When i try to compile i get this error:

main.obj : error LNK2019: unresolved external symbol "class DateProcessorClass __cdecl operator+(class DateProcessorClass const &,class DateProcessorClass const &)" (??H@YA?AVDateProcessorClass@@ABV0@0@Z) referenced in function _main
Debug/DateProcessorClass.exe : fatal error LNK1120: 1 unresolved externals
 

Any ideas?

[gasfusion]

errr... problem solved.
I was passing parameters as constants in my + operator function in the declaration of the function in the header file.

DateProcessorClass operator + (const DateProcessorClass& left, const DateProcessorClass& right);

Duh...