是否允许删除这个;如果删除语句是将在该类实例上执行的最后一条语句?当然,我确定this指针所表示的对象是新创建的。

我在想这样的事情:

void SomeModule::doStuff()
{
    // in the controller, "this" object of SomeModule is the "current module"
    // now, if I want to switch over to a new Module, eg:

    controller->setWorkingModule(new OtherModule());

    // since the new "OtherModule" object will take the lead, 
    // I want to get rid of this "SomeModule" object:

    delete this;
}

我能这样做吗?


当前回答

One of the reasons that C++ was designed was to make it easy to reuse code. In general, C++ should be written so that it works whether the class is instantiated on the heap, in an array, or on the stack. "Delete this" is a very bad coding practice because it will only work if a single instance is defined on the heap; and there had better not be another delete statement, which is typically used by most developers to clean up the heap. Doing this also assumes that no maintenance programmer in the future will cure a falsely perceived memory leak by adding a delete statement.

Even if you know in advance that your current plan is to only allocate a single instance on the heap, what if some happy-go-lucky developer comes along in the future and decides to create an instance on the stack? Or, what if he cuts and pastes certain portions of the class to a new class that he intends to use on the stack? When the code reaches "delete this" it will go off and delete it, but then when the object goes out of scope, it will call the destructor. The destructor will then try to delete it again and then you are hosed. In the past, doing something like this would screw up not only the program but the operating system and the computer would need to be rebooted. In any case, this is highly NOT recommended and should almost always be avoided. I would have to be desperate, seriously plastered, or really hate the company I worked for to write code that did this.

其他回答

只要对象在堆中,删除是合法的。 您需要要求对象仅为堆。 做到这一点的唯一方法是使析构函数受保护——这种方法可以从类中only调用delete,因此您需要一个方法来确保删除

c++ FAQ Lite中有一个专门的条目

https://isocpp.org/wiki/faq/freestore-mgmt#delete-this

我认为这句话很好地总结了这一点

只要你小心,对象自杀是可以的(删除这个)。

One of the reasons that C++ was designed was to make it easy to reuse code. In general, C++ should be written so that it works whether the class is instantiated on the heap, in an array, or on the stack. "Delete this" is a very bad coding practice because it will only work if a single instance is defined on the heap; and there had better not be another delete statement, which is typically used by most developers to clean up the heap. Doing this also assumes that no maintenance programmer in the future will cure a falsely perceived memory leak by adding a delete statement.

Even if you know in advance that your current plan is to only allocate a single instance on the heap, what if some happy-go-lucky developer comes along in the future and decides to create an instance on the stack? Or, what if he cuts and pastes certain portions of the class to a new class that he intends to use on the stack? When the code reaches "delete this" it will go off and delete it, but then when the object goes out of scope, it will call the destructor. The destructor will then try to delete it again and then you are hosed. In the past, doing something like this would screw up not only the program but the operating system and the computer would need to be rebooted. In any case, this is highly NOT recommended and should almost always be avoided. I would have to be desperate, seriously plastered, or really hate the company I worked for to write code that did this.

你可以这样做。然而,你不能给它赋值。因此,你陈述这样做的原因,“我想改变观点”,似乎很有问题。在我看来,更好的方法是让持有视图的对象替换该视图。

当然,你使用的是RAII对象所以你根本不需要调用delete,对吧?

这是允许的(只是在那之后不要使用对象),但我不会在实践中编写这样的代码。我认为delete this应该只出现在调用release或release的函数中,看起来像:void release() {ref——;If (ref<1);}。