How to get the index of a value in a vector using for_each?

Question

I have the following code (compiler: MSVC++ 10):

std::vector data;
data.push_back(1.0f);
data.push_back(1.0f);
data.push_back(2.0f);

// lambda          


        

Answer 1

You could also pass a struct as third argument to std::for_each and count the index in it like so:

struct myStruct {
   myStruct(void) : index(0) {};
   void operator() (float i) { cout << index << ": " << i << endl; index++; }
   int index;
};

int main()
{

   std::vector data;
   data.push_back(1.0f);
   data.push_back(4.0f);
   data.push_back(8.0f);

   // lambda expression
   std::for_each(data.begin(), data.end(), myStruct());

   return 0;
}