Std :: for_each using a member function with two arguments

Here's a general idea of ​​how my class is defined as (it performs other operations than what is indicated below)

struct Funktor
{
    Funktor(int val):m_val(val){}
    bool operator()(int arg1, int arg2) { return m_val==arg1*arg2; }
    int m_val;
};

And now I have a vector of the above objects and I'm trying to call operator () using for_each, is there any way to do this? I know that this can be done with bind2nd and mem_func_ref, but when there is only one argument, but for two arguments I did not find a way.

int main()
{
    std::vector<Funktor> funktors;
    funktors.push_back(Funktor(10));
    funktors.push_back(Funktor(20));
    funktors.push_back(Funktor(30));

    int arg1 = 5, arg2 = 6;
    //instead of the for loop below I want to use for_each
    for(std::vector<Funktor>::iterator itr = funktors.begin(); funktors.end() != itr; ++itr)
    {
        (*itr)(arg1,arg2);
   }
}

Thanks for any help. Best.

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1 answer

C ++ 03 Solution (no increase):

Write another functor as:

struct TwoArgFunctor
{
    int arg1, arg2;
    TwoArgFunctor(int a, int b) :arg1(a), arg2(b) {}

    template<typename Functor>
    bool operator()(Functor fun)
    {
        return fun(arg1, arg2); //here you invoke the actual functor!
    }
};

Then use it like:

std::for_each(funktors.begin(),funktors.end(), TwoArgFunctor(arg1,arg2));

C ++ 11 Solution:

std::for_each(funktors.begin(),funktors.end(), 
                         [&] (Funktor f) -> bool { return f(arg1,arg2); });
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