Question

Here is my C function definition:

//C
int FXForwardRate(
    long         *riskZCDates,      /* (I) Risk ZC dates */ 
    double       *fwdRate);         /*(O) Output */

the first parameter is actually pointing to an array of long.
In C# I would ideally like to call it like this:

//C#    
int[] array = {1,2,3}; //if i'm not mistaking long in C is int in :NET
double fwdRate = 0;

Class1.FXForwardRate(array, ref fwdRate);

Now for my C++/CLI code I don’t know how to declare the function in a Class1 class (I didn’t put the whole code to be concise):

//C++/CLI
int Class1::FXForwardRateW(int[] premium, double %fwdRate)
{
     double _tempFwdRate = 0.0;
     int _status = FXForwardRate(premium, &_tempFwdRate);
     fwdRate = _tempFwdRate;
     return _status;
}

I know from another function I wrote that what I did for the second parameter is right (not sure it’s the best method though). But how about the first one? Should I do the same thing? ie: define a pointer pass it to the C function and then copy the values back to the array?
Regards

Answer 1

The correct solution (both Lirik and pst gave pointers in the right direction) would be:

int Class1::FXForwardRateW(array<int>^ premium, double %fwdRate)
{
     double tempFwdRate = fwdRate;
     pin_ptr<int> premiumPtr = &premium[0];
     int status = FXForwardRate(premiumPtr, &tempFwdRate);
     fwdRate = tempFwdRate;
     return status;
}