auto_ptr // 头文件 <memory>
std::auto_ptr<ClassA> ptr1(new ClassA); // ok
std::auto_ptr<ClassA> ptr2 = new ClassA; // error 不允许 赋值(assign)初始化方式
auto_ptr赋值会导致所有权的转移
auto_ptr错误运用:
1.auto_ptr之间不能共享拥有的所有权
2.不能让auto_ptr指向数组，因为是透过delete而没有delete[
1.所有权的变更
#include <iostream> #include <memory> using namespace std; template <class T> ostream& operator<<(ostream& out, const auto_ptr<T>& p) { if(p.get() == NULL) out<<"NULL"; else out<<*p; return out; } int main() { auto_ptr<int> p(new int(42)); auto_ptr<int> q; cout<<"after init..\n"; cout<<"p = "<<p<<endl; cout<<"q = "<<q<<endl; q = p; cout<<"after assign..\n"; cout<<"p = "<<p<<endl; cout<<"q = "<<q<<endl; *q += 13; p = q; cout<<"after change and assign..\n"; cout<<"p = "<<p<<endl; cout<<"q = "<<q<<endl; }
输出结果:
after init..
p = 42
q = NULL
after assign..
p = NULL
q = 42
after change and assign..
p = 55
q = NULL
原文：http://www.cnblogs.com/sylar-liang/p/4326623.html