using of std::accumulate

Question

Need prettier solution of below example but with std::accumulate.

#include 
#include 
#include 

class Object
{
pu         


        

Answer 1

Using c++0x:

#include 
#include 
#include 

class Object
{
  public:
     Object( double a, double b ):
        a_( a ),
        b_( b )
      {}

    double GetA() const { return a_; }
    double GetB() const { return b_; }
    // other methods
  private:
    double a_;
    double b_;
};

int main()
{
    std::vector< Object > collection;
    collection.push_back( Object( 1, 2 ) );
    collection.push_back( Object( 3, 4 ) );
    double result = std::accumulate( collection.begin(), collection.end(), 0,
                                     [] (double result, const Object& obj) 
                                     {
                                       return result + obj.GetA() * obj.GetB();
                                     }
                                   ); 

   std::cout << "result = " << result << std::endl;

   return 0;
}