[C++知识库]C++primer plus 第八章：编程练习7

7. 修改程序清单8.14，使其使用两个名为SumArray()的模板函数来返回数组元素的总和，而不是显示数组的内容。程序应显示thing的总和以及所有debt的总和。?

// tempover.cpp --- template overloading
#include <iostream>
template <typename T>
T SumArray(T arr[], int n);

template <typename T>
T SumArray(T* arr[], int n);

struct debts
{
    char name[50];
    double amount;
};

int main()
{
    using namespace std;
    int things[6] = { 13, 31, 103, 301, 310, 130 };
    struct debts mr_E[3] =
    {
        {"Ima Wolfe", 2400.0},
        {"Ura Foxe", 1300.0},
        {"Iby Stout", 1800.0}
    };
    double* pd[3];

    // set pointers to the amount members of the structures in mr_E
    for (int i = 0; i < 3; i++)
        pd[i] = &mr_E[i].amount;
    cout << SumArray(things, 6) << endl; 
    cout << SumArray(pd, 3) << endl;
    return 0;
}

template <typename T>
T SumArray(T arr[], int n) {
    T sum=arr[0];
    for (int i = 1; i < n; i++) 
        sum += arr[i];
    return sum;
}

template <typename T>
T SumArray(T* arr[], int n) {
    T sum = *arr[0];
    for (int i = 1; i < n; i++)
        sum += *arr[i];
    return sum;
}