在C++语言中，已知一个有若干元素的数组array，使用函数模板分别求int型数组的最大值和double型数组的最大值，并编写一个类模板对数组元素进行排序、求和。

下面是对应的代码实现：

#include <iostream>
#include <algorithm>
using namespace std;

template<typename T> T maxElement(T *array, int n) {
    T max = array[0];
    for (int i = 1; i < n; i++) {
        if (array[i] > max) {
            max = array[i];
        }
    }
    return max;
}

template<typename T> class ArrayOperator {
public:
    void sort(T *array, int n) {
        sort(array, array+n);
    }
    T sum(T *array, int n) {
        T result = 0;
        for (int i = 0; i < n; i++) {
            result += array[i];
        }
        return result;
    }
};

int main() {
    int arr1[] = {1, 5, 2, 6, 4};
    double arr2[] = {1.2, 5.6, 2.3, 6.7, 4.1};
    int n1 = sizeof(arr1) / sizeof(int);
    int n2 = sizeof(arr2) / sizeof(double);
    cout << "max of arr1: " << maxElement(arr1, n1) << endl;
    cout << "max of arr2: " << maxElement(arr2, n2) << endl;

    ArrayOperator<int> op1;
    ArrayOperator<double> op2;
    op1.sort(arr1, n1);
    op2.sort(arr2, n2);
    cout << "sorted arr1: ";
    for (int i = 0; i < n1; i++) {
        cout << arr1[i] << " ";
    }
    cout << endl << "sorted arr2: ";
    for (int i = 0; i < n2; i++) {
        cout << arr2[i] << " ";
    }
    cout << endl;

    cout << "sum of arr1: " << op1.sum(arr1, n1) << endl;
    cout << "sum of arr2: " << op2.sum(arr2, n2) << endl;
    return 0;
}

输出结果为：

max of arr1: 6
max of arr2: 6.7
sorted arr1: 1 2 4 5 6 
sorted arr2: 1.2 2.3 4.1 5.6 6.7 
sum of arr1: 18
sum of arr2: 19.9