C++ primer 构造、析构、赋值测试

复制构造函数在书上列举了五种应用场景，但在G++上发现，在从函数返回时，并不调用复制构造函数

/*
** Copyright (C) QPSOFT.COM All rights reserved.
*/
#include<string>
#include<vector>
#include<iostream>
using namespace std;
class Employee
{
public:
    Employee() : name ("NoName"), id (counter)
    {
        cout << "不带参数的构造函数！" << "/t" << ++counter << endl;
    }
    Employee (std::string nm) : name (nm), id (counter)
    {
        cout << "带参数的构造函数：" << "/t" << (++counter)
             << "/tEmployee (std::string nm) " << endl;
    }
    Employee (const Employee& other) : name (other.name), id (counter)
    {
        cout << "复制构造函数！" <<  "/t" << ++counter << endl;
    }
    Employee& operator= (const Employee& rhe)
    {
        name = rhe.name;
        cout << "‘=’运算符重载" << endl;
        return *this;
    }
    ~Employee()
    {
        cout << "析构函数" << "/t" << (counter--) << endl;
    }
private:
    std::string name;
    int id;
    static int counter;
};
int Employee::counter = 0;
void fun1 (Employee obj) {}
void fun2 (Employee& obj) {}
Employee fun3()
{
    Employee obj;//不带参数构造函数
    return obj;
}
int main()
{
    Employee ep;//默认构造函数
    Employee ab;
    Employee sep ("iString");
    ab = ep; //=重载
    Employee tp = ep; //复制构造函数
    vector<Employee> iep(5);//复制构造函数
    iep.push_back (ep); //复制构造函数
    iep.push_back (ab); //复制构造函数
    Employee ee[] = {ep, ab, ep, ep, ab}; //会调用复制构造函数
    cout << "----------下面是函数测试----------------" << endl;
    fun1 (ep); //复制 然后析构
    cout << "-----------------------------------------"<<endl;
    fun2 (ep);
    cout << "---------------丢弃返回的fun3----------------"<<endl;
    fun3();
    cout << "---------------保存返回的fun3------------"<<endl;
    ab = fun3();
    cout << "---------程序返回!------------------------" << endl;
    return 0;
}