日积月累: Uncopyable & Uninheritable in C++

November 13, 2009 4:45 pm /

如何在C++中阻止复制和继承呢，我做了个整理。

Uncopyable
有些类需要禁止被复制或者赋值，这需要显示的禁掉它们的拷贝构造和赋值函数。
摘自《Effective C++》Item 6: Explicitly disallow the use of compiler-generated functions you do not want

class Uncopyable 
{
protected:                                   // allow construction
    Uncopyable() {}                       // and destruction of
    ~Uncopyable() {}                     // derived objects...

private:
    Uncopyable(const Uncopyable&);             // ...but prevent copying
    Uncopyable& operator=(const Uncopyable&);
};

class UncopyableExample: private Uncopyable 
{ 
    // THIS CLASS IS UNCOPYABLE
};

Uninheritable
Java提供了final关键字用来阻止被继承，而在C++中没有这个关键字，但阻止继承的类在C++中是同样可能的。
摘自：http://www.csse.monash.edu.au/~damian/Idioms/Topics/04.SB.NoInherit/html/text.html

template <class OnlyFriend>
class Uninheritable
{
    friend class OnlyFriend;
    Uninheritable(void) {}
};

class NotABase : virtual public Uninheritable< NotABase >
{
    // WHATEVER
};

class NotADerived: public NotABase
{
    // THIS CLASS GENERATES A COMPILER ERROR
    NotADerived(){}
};
Posted in: C++, Talking in Code / Tagged: , ,

7 Thoughts on “日积月累: Uncopyable & Uninheritable in C++”

  1. chenhong on November 13, 2009 at 10:57 pm said:

    学习了，呵呵

  2. orange on November 14, 2009 at 5:56 am said:

    啊。。专家。。

  3. Benny on November 14, 2009 at 12:20 pm said:

    呵呵，我只是转载做份收藏而已~

  4. Pingback: Music Sets Me Free » Blog Archive » 让管理lua_State的类指针安全

  5. Pingback: 让管理lua_State的类指针安全 | Nutty Coder

  6. starfish on July 16, 2011 at 10:59 pm said:

    Uninheritable的实现有问题，大部分编译器都无法编译通过。
    因为C++的标准中禁止将模板参数作为friend

Post Navigation