聚合：“雁群”是對“大雁”的聚合[1]。
class DaYan
{
//......
};
class YanQun
{
vector v_DaYan;
public:
void fly()
{
for_each(v_DaYan.begin(),v_DaYan.end(),fly);
}
};
class DaYan
{
//......
};
class YanQun
{
vector
public:
void fly()
{
for_each(v_DaYan.begin(),v_DaYan.end(),fly);
}
};