C ++：任何方式来防止抽象基类的任何实例化？ [英] C++: any way to prevent any instantiation of an abstract base class?

问题描述

除了有一个纯虚函数，有没有办法阻止抽象基类的实例化？

我可以这样做：

  class BaseFoo 
 {
 virtual void blah（）= 0; 
}; 
 
 class Foo：public BaseFoo 
 {
 virtual void blah（）{} 
}; 
  

但我想避免vtable。 （按照我有关虚拟析构函数的其他问题）

Microsoft ATL有ATL_NO_VTABLE来实现这一点（至少我认为这是它的作用...）

这当然会将corectness的负担转移到派生类，但至少基类是受保护的。

Aside from having a pure virtual function, is there a way to prevent an instantiation of an abstract base class?

I can do this:

class BaseFoo
{
    virtual void blah() = 0;
};

class Foo : public BaseFoo
{
    virtual void blah() {}
};

but I'd like to avoid a vtable. (as per my other question about virtual destructors)

Microsoft ATL has ATL_NO_VTABLE to accomplish this (or at least I think that's what it does...)

解决方案

A really obvious way is to declare a protected constructor, and to declare public constructors in the non-abstract derived classes.

This of course shifts the burden of corectness to the derived classes, but at least the base class is protected.

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