cpp-Primer-Plus-6e-Notes/Chapter16/initializer_list.cpp at master · SolerHo/cpp-Primer-Plus-6e-Notes · GitHub

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// initializer_list 实例 C++11 新特性

#include <iostream>
#include <initializer_list>

double sum(std::initializer_list<double> il);
double average(const std::initializer_list<double> & ril);

int main()
{
    using namespace std;
    cout << "List 1 : sum = " << sum({2,3,4})
         <<", ave = " << average({2,3,4}) << "\n";
    std::initializer_list<double> d1 = {1.1,2.2,3.3,4.4,5.5};
    cout << "List 2 : sum = " <<sum(d1)
         << ", ave = " << average(d1) << "\n";
    d1 = {16.0,25.0,36.0,40,0,64.0};
    cout << "List 3 : sum = " <<sum(d1)
         << ", ave = " << average(d1) << "\n";

    return 0;
}

double sum(std::initializer_list<double> il)
{
    double tot = 0;
    for (auto p = il.begin(); p != il.end();p++)
        tot += *p;
    return tot;
}

double average(const std::initializer_list<double> &ril)
{
    double tot = 0;
    int n = ril.size();
    double ave = 0.0;
    if (n > 0)
    {
        for (auto p = ril.begin(); p != ril.end();p++)
            tot += *p;
        ave = tot / n;
    }
    return ave;
}