c++ - ptr_vector 未正确释放

Question

我正在尝试使用 ptr_vector 来存储一些指针，但是我的 main 方法一启动就出现错误。 这是我的代码:

int main(void)
{
    boost::ptr_vector<string> temp;
    string s1 = "hi";
    string s2 = "hello";
    temp.push_back(&s1);
    temp.push_back(&s2);
    return 0;
}

这是我收到的错误消息:

Critical error detected c0000374
Windows has triggered a breakpoint in Path_Tree.exe.

This may be due to a corruption of the heap, which indicates a bug in Path_Tree.exe or     any of the DLLs it has loaded.

This may also be due to the user pressing F12 while Path_Tree.exe has focus.

The output window may have more diagnostic information.
The program '[7344] Path_Tree.exe: Native' has exited with code 0 (0x0).

我做错了什么？ 谢谢!

Answer 1

ptr_vector 获取您提供给它的指针指向的对象的所有权(这意味着它在完成这些指针后调用 delete)。如果您只需要一个指针 vector ，请使用:

int main()
{
    std::vector<string*> temp;
    //s1 and s2 manage their own lifetimes
    //(and will be destructed at the end of the scope)
    string s1 = "hi";
    string s2 = "hello";
    //temp[0] and temp[1] point to s1 and s2 respectively
    temp.push_back(&s1);
    temp.push_back(&s2);
    return 0;
}

否则，您应该使用 new 分配您的字符串，然后 push_back 结果指针:

int main()
{
    boost::ptr_vector<string> temp;
    temp.push_back(new string("hi"));
    temp.push_back(new string("hello"));
    return 0;
}

如果您只需要一个字符串容器，通常的做法是字符串 vector :

int main()
{
    std::vector<string> temp;
    //s1 and s2 manage their own lifetimes
    //(and will be destructed at the end of the scope)
    string s1 = "hi";
    string s2 = "hello";
    //temp[0] and temp[1] refer to copies of s1 and s2.
    //The vector manages the lifetimes of these copies,
    //and will destroy them when it goes out of scope.
    temp.push_back(s1);
    temp.push_back(s2);
    return 0;
}

ptr_vector 旨在使具有值语义的多态对象变得更容易。如果您的字符串一开始就不是多态的，那么 ptr_vector 就完全没有必要了。