Off the top of me head:
#include <iostream>
#include <conio.h>
using std::cout;
using std::endl;
struct TData
{
float fWeight;
float fLength;
};
typedef float (TData::*TDataFloatPointer); // pointer to member
float CalcAverage(const TData* pArray, int iSize, TDataFloatPointer p)
{
float fAverage = 0;
for(int i = 0; i < iSize; ++i)
{
float f = pArray->*p; // derefernce through the pointer to member
fAverage += f;
++pArray;
}
return fAverage/iSize;
}
void PrintArrayData(const TData* pArray, int iSize, TDataFloatPointer p)
{
float fAverage = CalcAverage(pArray, iSize, p);
for(int i = 0; i < iSize; ++i)
cout << pArray++->*p << endl;
cout << "Average:" << endl << fAverage << endl;
}
int main()
{
const TData vData[] =
{
{ 1.0f, 10.0f },
{ 2, 9 },
{ 3, 8 },
{ 4, 7 },
{ 5, 6 },
{ 6, 5 },
{ 7, 4 },
{ 8, 3 },
{ 9, 2 },
{ 10, 1 }
};
const NUM_DATA = sizeof(vData)/sizeof(vData[0]);
cout << "Weights:" << endl;
PrintArrayData(vData, NUM_DATA, &TData::fWeight); // get the pointer to member
cout << "Length:" << endl;
PrintArrayData(vData, NUM_DATA, &TData::fLength);
getch();
}
Using a pointer to member construct, this will collect each member's weight or length and return an average.
Pointers to members are a niche type of programing mechanism. There are very few instances where pointers to members are even useful, but the times they are, they're invaluable. They're most useful, in my experince, in certain forms of automation, such as running the same algorithm over different members of the same type. Thus particular example could be boiled down to about 10 lines of code were I to go further w/ the pointers to members and templates, but this is a much more clear example.
Hope it helps!
Offline 
TMemberPointer)
, or you're running an algo on many parts of it. 
Unsolved 
