make shared_ptr不使用delete

in my code i would like boost::shared_ptr not to call delete but call ptr->deleteMe() instead.

在我的代码中，我想boost :: shared_ptr不要调用delete但是调用ptr-> deleteMe（）代替。

Also i have a few C styled functions that return a ptr. Can i make it call lib_freeXYZ(ptr); instead of trying to delete?

我还有一些C风格的函数返回一个ptr。我可以调用lib_freeXYZ（ptr）;而不是试图删除？

4 个解决方案

#1

Or how about using the stl to provide the wrapper functor - Doug T. description but without the custom caller.

或者如何使用stl提供包装函数 - Doug T.描述但没有自定义调用者。

boost::shared_ptr<T> ptr( new T, std::mem_fun_ref(&T::deleteMe) );
boost::shared_ptr<S> ptr( new S, std::ptr_fun(lib_freeXYZ) );

#2

You can give the shared_ptr template a custom deleter function which has the signature

您可以为shared_ptr模板提供具有签名的自定义删除函数

  void Deleter( T* ptr);

for a boost::shared_ptr

对于boost :: shared_ptr

So for Deleter you would do

所以对于Deleter你会这样做

  boost::shared_ptr<T> ptrToT( new T, Deleter );

then in the body of Deleter:

然后在Deleter的身体：

   void Deleter( T* ptr);
   {
        ptr->deleteMe();
        // And make sure YOU ACTUALLY DELETE (or do whatever else you need to
        // do to release the resource)
        delete ptr;
   }

For your specific case when you need something simple (like ptr->deleteMe) see Greg's solution, its very nice.

对于您需要简单的特定情况（如ptr-> deleteMe），请参阅Greg的解决方案，非常好。

#3

Doug T. answered your question nicely. I'll tell you about intrusive_ptr. Maybe you can use it in your project too.

Doug T.很好地回答了你的问题。我会告诉你关于intrusive_ptr的事。也许你也可以在你的项目中使用它。

If you have some C library that has already reference counting, but you have to manually call those functions, you can use boost::intrusive_ptr too, and provide proper definitions for its add_ref and release functions. intrusive_ptr will find and call them. They are responsible to increment the reference count and decrement it, freeing the resource when necassary:

如果你有一些已经引用计数的C库，但你必须手动调用这些函数，你也可以使用boost :: intrusive_ptr，并为其add_ref和release函数提供正确的定义。 intrusive_ptr会找到并调用它们。他们负责增加引用计数并减少它，在需要时释放资源：

void intrusive_ptr_add_ref(foo *f) {
    lib_add_ref(f);
}

void intrusive_ptr_release(foo *f) {
    if(lib_dec_ref(f) == 0) 
        lib_free(f);
}

Then you can just create objects from raw pointers of type foo*. intrusive_ptr will call your functions when its copied/destructed:

然后你可以从foo *类型的原始指针创建对象。 intrusive_ptr将在复制/销毁时调用您的函数：

intrusive_ptr<foo> f(lib_alloc());

// can wrap raw pointers too, which already may be referenced somewhere else
foo *p = get_foo_from_somewhere();
function_taking_intrusive_ptr(p);

#4

For the C-style data, do as @Doug. T suggested.

对于C风格的数据，请执行@Doug。 T建议。

For your class, why not do cleanup in a destructor? Even if this is including deleteMe() in the destructor.

对于你的班级，为什么不在析构函数中进行清理？即使这是在析构函数中包含deleteMe（）。

#1