string& foo()
{
string* str = new string("abc");
return *str; 
}

struct a_s
{
int a;
};

a_s* foo()
{
  struct a_s* sp = new struct a_s;
  return sp;
}

string& tmp = foo();
string str = tmp; 
delete &tmp;

#include <iostream>
using namespace std;
class example
{
public:
example()
{
  num = new int;
  *num = 10;
  cout<<"num = "<<*num<<endl;
  cout<<"构造"<<endl;
}
~example()
{
  cout<<"析构"<<endl;
  delete num;
}
void pingfang()
{
  *num *= *num;
}
void print()
{
  cout<<*num<<endl;
}
private:
int *num;
};

example & diaoyong1()
{
example * p = new example;
p->pingfang();
return *p;
}

example * diaoyong2()
{
example * p = new example;
p->pingfang();
return p;
}

int main(void)
{
example & e1 = diaoyong1();
e1.print();
delete &e1;
example * ptr = diaoyong2();
ptr->print();
delete ptr;
getchar();
return 0;
}