Summing struct members inside a vector

Question

Consider the following:

typedef struct {
    int a;
    int b;
    int c;
    int d;
} ABCD;

typedef std::vector VecABCD;

Say

Answer 1

You could use for_each. Its an option.

#include 
#include 
#include 

using namespace std;
typedef struct{
    int a;

}ABCD;

typedef vector vecABCD;

struct sum  : public unary_function
{
  sum(){count.a=count.b=count.c=count.d=0;}
  void operator() (ABCD x) {
       count.a+=x.a;
       count.b+=x.b;
       count.c+=x.c;
       count.d+=x.d;
   }
  ABCD count;
};

int main()
{

  ABCD s1={1,2,3,4};
  ABCD s2={5,6,7,8};

  vecABCD v;
  v.push_back(s1);
  v.push_back(s2);
  sum s = for_each(v.begin(), v.end(), sum());
  cout<

output:

4