使用聚合体

聚合体就是“类的集合的类”

#include <iostream>
#include <string>
#include <vector>

using namespace std;

class Critter 
{
public:
    Critter(const string& name = "");
    string GetName() const;
private:
    string m_Name;
};

Critter::Critter(const string& name) :
    m_Name(name)
{}

inline string Critter::GetName() const
{
    return m_Name;
}

// 聚合体
class Farm
{
public:
    Farm(int spaces = 1);
    void Add(const Critter& aCritter);
    void RollCall() const;
private:
    vector<Critter> m_Critters; // 容器数据成员
};

Farm::Farm(int spaces)
{
    m_Critters.reserve(spaces);
}

void Farm::Add(const Critter& aCritter)
{
    m_Critters.push_back(aCritter);
}

void Farm::RollCall() const
{
    for (vector<Critter>::const_iterator iter = m_Critters.begin();
        iter != m_Critters.end();
        ++iter
        )
    {
        cout << iter->GetName() << " here.\n";
    }
}

int main()
{
    Critter crit("Poochie");
    cout << "My critter's name is " << crit.GetName() << endl;
    cout << "Creating critter farm.\n";
    Farm myFarm(3);
    cout << "\nAdd three critters to the farm.\n";
    myFarm.Add(Critter("Moe"));
    myFarm.Add(Critter("Larry"));
    myFarm.Add(Critter("Curly"));
    cout << "\nCalling Roll...\n";
    myFarm.RollCall();
    return 0;
}