在C ++中删除对象 [英] Deleting an object in C++

问题描述

这里是一个示例代码：

void test()
{
   Object1 *obj = new Object1();
   .
   .
   .
   delete obj;
}

我在Visual Studio中运行它， obj;'。
这不是正常的方式来释放与对象相关的内存吗？
我意识到它会自动调用析构函数...这是正常的吗？

I run it in Visual Studio, and it crashes at the line with 'delete obj;'. Isn't this the normal way to free the memory associated with an object? I realized that it automatically invokes the destructor... is this normal?

这里是一个代码片段：

    if(node->isleaf())
    {
        vector<string> vec = node->L;
        vec.push_back(node->code);
        sort(vec.begin(), vec.end());

        Mesh* msh = loadLeaves(vec, node->code);

        Simplification smp(msh);

        smp.simplifyErrorBased(errorThreshold);

        int meshFaceCount = msh->faces.size();

        saveLeaves(vec, msh);

        delete msh;
    }

loadleaves（）是一个从磁盘读取网格并创建 Mesh 对象并返回它的函数（考虑 vec code> node-> code 只是关于要打开的文件的信息）

loadleaves() is a function that reads a mesh from disk and creates a Mesh object and returns it.(think of vec and node->code are just information about the file to be opened)

c> delete msh; line？

Should I remove the delete msh; line?

推荐答案

释放与对象相关联的内存的正常方式？

Isn't this the normal way to free the memory associated with an object?

这是管理动态分配的内存的常见方法，但它不是好的方法这样做。这种代码很脆弱，因为它不是异常安全的：如果在创建对象和删除对象之间抛出异常，你将泄漏该对象。

This is a common way of managing dynamically allocated memory, but it's not a good way to do so. This sort of code is brittle because it is not exception-safe: if an exception is thrown between when you create the object and when you delete it, you will leak that object.

最好使用智能指针容器，你可以使用它来获取范围绑定的资源管理（更常见的是，或者RAII）。资源获取是资源获取的初始化。

It is far better to use a smart pointer container, which you can use to get scope-bound resource management (it's more commonly called resource acquisition is initialization, or RAII).

作为自动资源管理的示例：

As an example of automatic resource management:

void test()
{
    std::auto_ptr<Object1> obj1(new Object1);

} // The object is automatically deleted when the scope ends.

根据您的用例， auto_ptr 不提供你需要的语义。在这种情况下，您可以考虑使用 shared_ptr 。

Depending on your use case, auto_ptr might not provide the semantics you need. In that case, you can consider using shared_ptr.

至于为什么当您删除对象时程序崩溃，你没有给予足够的代码，任何人都能够肯定地回答这个问题。

As for why your program crashes when you delete the object, you have not given sufficient code for anyone to be able to answer that question with any certainty.

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