Функциональные адаптеры

#include <iostream>
#include <algorithm>
 
using namespace std;
 
template<class Operation, class T>
binder2nd <Operation> bind2nd (const Operation& op, const T& x)
{
    return binder2nd<Operation>(
        op, typename
        Operation::second_argument_type(x)
        );
}
 
struct multiplies2:unary_function<int, int>
{
    bool operator()(int x) const { return x * 0.5; }
};
 
int main()
{
    int mas[] = { 2, 50, 8, 10, 110, 34, 48, 78, 24 };
    
    for_each(mas, mas + 9, bind2nd(multiplies<int>(), 0.5));
    
    for (int i = 0; i < 9; i++) cout << mas[i] << " ";
    cout << endl;
 
    return 0;
}

void modify(int* arr, int* end)
{
    std::transform(arr, end, arr, std::bind(std::divides<int>(), std::placeholders::_1, 2));
}

template <typename T>
struct Divides : std::unary_function<T, void>
{
    void operator()(T& x) const { x /= 2; }
};
 
int main()
{
    int mas[] = { 2, 50, 8, 10, 110, 34, 48, 78, 24 };
    std::for_each(mas, mas + 9, Divides<int>());
 
    for (int i = 0; i < 9; i++) std::cout << mas[i] << " ";
    std::cout << std::endl;
}

template <typename T>
struct Divides : std::binary_function<T, T, void>
{
    void operator()(T& x, const T& val) const { x /= val; }
};
 
int main()
{
    int mas[] = { 2, 50, 8, 10, 110, 34, 48, 78, 24 };
    std::for_each(mas, mas + 9, std::bind2nd(Divides<int>(), 2));
 
    for (int i = 0; i < 9; i++) std::cout << mas[i] << " ";
    std::cout << std::endl;
}