逆序打印cout

Question

尝试重载以下示例中的运算符()：

#include <iostream>
using namespace std;

class Fib {
  public:
    Fib() : a0_(1), a1_(1) {}
    int operator()();
  private:
    int a0_, a1_;
};
int Fib::operator()() {
    int temp = a0_;
    a0_ = a1_;
    a1_ = temp + a0_;
    return temp;
}

int main() {
    Fib fib;

    cout << fib() <<"," << fib() << "," << fib() << "," << fib() << "," << fib() << "," << fib() << endl;
}

它以相反的顺序打印fib序列: 8,5,3,2,1,1。我知道状态保持在() overlading中，但是为什么打印是以相反的顺序显示的？

Answer 1

operator <<是为其参数定义的某个函数。未指定函数参数的求值顺序。它们可以从右到左或从左到右进行评估。看起来你的编译器从右到左对它们求值。