cppReduceFPtr

#include <iostream>

template <typename T>
void printArr(const T* begin, const T* const end)
{
    while (begin != end)
    {
        std::cout << *begin++ << ' ';
    }
    std::cout << '\n';
}

template <typename T, typename ReduceFunc>
T reduce(const T* begin, const T* const end, ReduceFunc reduceFunc, T initialValue)
{
    while (begin != end)
    {
        initialValue = reduceFunc(initialValue, *begin++);
    }
    return initialValue;
}

template <typename T>
T sum(const T& prev, const T& curr)
{
    return prev + curr;
}

template <typename T>
T max(const T& prev, const T& curr)
{
    return prev > curr ? prev : curr;
}

template <typename T>
T join(const T& prev, const T& curr)
{
    return prev * 10 + curr;
}

int main()
{
    const int arrSize{ 10 };
    int arr[arrSize]{ 1,2,3,4,5,6,7,8,9,10 };

    std::cout << "sum = " << reduce(arr, arr + arrSize, sum<int>, 0) << '\n';
    std::cout << "max = " << reduce(arr, arr + arrSize, max<int>, 0) << '\n';
    std::cout << "join = " << reduce(arr, arr + 5, join<int>, 0) << '\n';

}