Can I add a value to all members of an Array

Question

Is there an algorithm in STL that can add at once the same value to all the members of an array?

For example:

KnightMoves moveKnight(int currentPossition_x, int currentPossition_y)
{
    array<int , 8> possibleMoves_x = { -2 , -2 , -1 , -1 ,  1 , 1 , 2 ,  2 };
    array<int , 8> possibleMoves_y = { -1 ,  1 , -2 ,  2 , -2 , 2 , -1 , 1 };

    for (auto it = possibleMoves_x.begin(); it != possibleMoves_x.end(); it++)
    {
        array <int, 8> newTempKnightPoss_x = currentPossition_x + possibleMoves_x;

        array <int, 8> newTempKnightPoss_y = currentPossition_y + possibleMoves_x;
    }

}

I could do something like this but i was hopping there is a better solution

KnightMoves moveKnight(int currentPossition_x, int currentPossition_y)
{
   array<int , 8> possibleMoves_x = { -2 , -2 , -1 , -1 ,  1 , 1 , 2 ,  2 };
   array<int , 8> possibleMoves_y = { -1 ,  1 , -2 ,  2 , -2 , 2 , -1 , 1 };

   for (auto it = possibleMoves_x.begin(); it != possibleMoves_x.end(); it++)
   {
       *it = *it  +currentPossition_x;

   }
   for (auto it = possibleMoves_y.begin(); it != possibleMoves_y.end(); it++)
   {
       *it = *it + currentPossition_y;

   }
}

The axpepted results are 2 arrays which each element is the element plus a constant value;

Answer 1

If you have C++11 you can use the range-based-for loop:

KnightMoves moveKnight(int currentPossition_x, int currentPossition_y){
    array<int , 8> possibleMoves_x = { -2 , -2 , -1 , -1 ,  1 , 1 , 2 ,  2 };
    array<int , 8> possibleMoves_y = { -1 ,  1 , -2 ,  2 , -2 , 2 , -1 , 1 };

    for(auto& i : possibleMoves_x){ i += currentPossition_x; }
    for(auto& i : possibleMoves_y){ i += currentPossition_y; }
}

Before C++11 you can use std::for_each :

struct adder{
    adder(int val): v{val}{}
    void operator()(int& n) { n += v; }
    int v;
};

KnightMoves moveKnight(int currentPossition_x, int currentPossition_y){
    array<int , 8> possibleMoves_x = { -2 , -2 , -1 , -1 ,  1 , 1 , 2 ,  2 };
    array<int , 8> possibleMoves_y = { -1 ,  1 , -2 ,  2 , -2 , 2 , -1 , 1 };

    std::for_each(possibleMoves_x.begin(), possibleMoves_x.end(), 
                  adder(currentPossition_x));
    std::for_each(possibleMoves_y.begin(), possibleMoves_y.end(),
                  adder(currentPossition_x));
}