纯成员函数 [英] pure member functions
问题描述
我试图创建一个抽象类，让非虚拟成员
函数为纯，但是我得到了编译错误说只有虚拟的
成员函数可以是纯粹的...
我正在考虑这个限制背后的原因...我只是希望
想要一个基类是抽象的，以避免从派生类型切换到基类型的对象切换到基础类型，在我的情况下基类没有
需要有一个虚拟功能。
还有其他选择吗？只有虚拟
成员函数纯粹的原因是什么？
Hi,
I tried to create a abstract class by having a non-virtual member
function as pure, but i got a compilation error saying "only virtual
member functions can be pure"...
I''m trying to think the reason behind this restriction... i just want
to want a base class to be abstract so as to avoid object slicing into
the base type from derived type, and in my case base class doesn''t
need to have a virtual function.
Is there any alternative? and what is the reason behind only virtual
member functions being pure?
推荐答案
12月18日晚上11:52 ，Rahul< sam _... @ yahoo.co.inwrote：
On Dec 18, 11:52 pm, Rahul <sam_...@yahoo.co.inwrote:
我试图创建一个通过拥有一个非虚拟成员的抽象类
作为纯函数，但我得到一个编译错误说只有虚拟
成员函数可以是纯粹的...... br />
我正在考虑这个限制背后的原因...我只想要
想要一个基类是抽象的，以避免对象从派生类型切入
基类型，在我的情况下基类不需要
需要有虚函数。
还有其他选择吗？只有虚拟
成员函数纯粹背后的原因是什么？
Hi,
I tried to create a abstract class by having a non-virtual member
function as pure, but i got a compilation error saying "only virtual
member functions can be pure"...
I''m trying to think the reason behind this restriction... i just want
to want a base class to be abstract so as to avoid object slicing into
the base type from derived type, and in my case base class doesn''t
need to have a virtual function.
Is there any alternative? and what is the reason behind only virtual
member functions being pure?
如果你没有任何虚函数，可能至少你会得到一个虚拟析构函数。
虚拟析构函数。使它纯净，提供实现。如果一个
非虚拟函数是纯粹的 - 你会如何覆盖它？如果你
不会覆盖它，那是什么意思？没有。所以，没有必要使用这样的会员。
If you don''t have any virtual function, probably atleast you will have
a virtual destructor. Make it pure, provide an implementation. IF a
non-virtual function is pure - how would you override it? And if you
will not override it, what does it mean? Nothing. So, no use having
such members.
2007-12-18 13:52:49 -0500，Rahul< sa * ****@yahoo.co.insaid：
On 2007-12-18 13:52:49 -0500, Rahul <sa*****@yahoo.co.insaid:
我试图创建一个抽象类一个非虚拟成员
作为纯函数，但是我得到了一个编译错误，说只有虚拟
成员函数可以是纯粹的......
我正在考虑这个限制背后的原因...我只想要
想要一个基类是抽象的，以避免对象切入
来自派生类型的基类型，在我的情况下基类没有
需要有一个虚函数。
Hi,
I tried to create a abstract class by having a non-virtual member
function as pure, but i got a compilation error saying "only virtual
member functions can be pure"...
I''m trying to think the reason behind this restriction... i just want
to want a base class to be abstract so as to avoid object slicing into
the base type from derived type, and in my case base class doesn''t
need to have a virtual function.
我不明白你的目标。你是什么意思对象切换成
派生类型的基本类型？
I don''t understand your goal. What do you mean by "object slicing into
the base type from derived type?"
>
还有其他选择吗？只有虚拟
成员函数纯粹背后的原因是什么？
>
Is there any alternative? and what is the reason behind only virtual
member functions being pure?
-
-kira
--
-kira
12月18日晚上11点56分，Abhishek Padmanabh< abhishek.padman ... @ gmail.com>
写道：
On Dec 18, 11:56 pm, Abhishek Padmanabh <abhishek.padman...@gmail.com>
wrote:
12月18日晚上11点52分，Rahul< sam _... @ yahoo.co.inwrote：
On Dec 18, 11:52 pm, Rahul <sam_...@yahoo.co.inwrote:
Hi,
我尝试通过将非虚拟成员
函数作为纯函数来创建抽象类，但是我得到了一个编译错误，说只有虚拟
成员函数可以是纯粹的... ...
I tried to create a abstract class by having a non-virtual member
function as pure, but i got a compilation error saying "only virtual
member functions can be pure"...
我正在考虑这个限制背后的原因..我只想要
想要一个基类是抽象的，以避免对象切换到派生类型的基本类型
，在我的情况下基类没有'$
需要有虚拟功能。
I''m trying to think the reason behind this restriction... i just want
to want a base class to be abstract so as to avoid object slicing into
the base type from derived type, and in my case base class doesn''t
need to have a virtual function.
还有其他选择吗？只有虚拟
成员函数纯粹背后的原因是什么？
Is there any alternative? and what is the reason behind only virtual
member functions being pure?
如果你没有虚函数，可能至少你会得到一个虚拟析构函数。使它纯净，提供实现。如果一个
非虚拟函数是纯粹的 - 你会如何覆盖它？如果你
不会覆盖它，那是什么意思？没有。所以，没有必要使用这样的会员。
If you don''t have any virtual function, probably atleast you will have
a virtual destructor. Make it pure, provide an implementation. IF a
non-virtual function is pure - how would you override it? And if you
will not override it, what does it mean? Nothing. So, no use having
such members.
是的，你可能是指当前的标准和
c ++的实现，然而，当bb标准正在制定中，有些人可能会想到纯粹的普通会员功能和一种机制来覆盖他们......因为某些原因他们还没有完成那......这是我想知道的......
Yes, you are probably referring to current standards and
implementation of c++,
however, when the standard was being developed, some one could have
thought of pure ordinary member functions and a mechanism to override
them too... for some reason they haven''t done that... which is what i
was wondering about...
这篇关于纯成员函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
