Which members are created automatically, which members are not inherited?

L

lovecreatesbeauty

I'm disturbed on this question on a long time. I think if I finally get
understand it with your kind help, I will get close to a excellent C++
programmer. And I only can rely on your expertise and help. I've read
some books, but no book focuses on this. Don't you think it is a very
important thing of C++ programming language? So your knowledge is of
great benefit to others, especially me.


1. Which (How many) members will be created automatically?

Scott Meyers seems to give this list in a early print of his
<<effective C++, 2nd>>, but he removed 1 (or 2, perhaps you know it),
the list containing 6 members he gives is:

default constructor, copy constructor, destructor, assignment
operator, a pair of address-of operators (i.e. const, non-const) .

But in a later print (not a new edition, I don't read the 3rd one) he
removed the last pair of operators from that list without a detail
description, or he put that pair in that list before without a
thoroughly convinced reason. That is my complaint.

Dr. Bjarne Stroustrup mentioned operator , (i.e. comma) is also a
predefined member (he mentioned total 3: =, &, and , in TC++PL sec
11.2.2), but Andrew Koenig said "That is not a member function." in my
post before. Obviously, it is inside a class body, so I do not
understand what he said.

Herb Sutter mentioned &&, || and , (comma) in his new book C++ coding
standard. But he did not give a complete list of automatically created
class members also. He always talks about some magic things on usage of
vector, list or some similar things with gurus. That is my complaint.

How about new and delete, and some others functions or operators which
I do not know the name. Who will give a complete list?


2. Which (How many) members can not be inherited?

I know default ctor, copy ctor, dctor, assignment operator can not be
inherited. The first three members share the same name respectively
even the base class name and the derived class name are different - it
is obvious, but it helps me to understand the reason of non-inherited.
I can understand operator assignment will not be inherited also.

But I am not sure if there are other members also can not be inherited.

How about new and delete, and some others functions or operators which
I do not know the name. Who will give a complete list?


Sincerely,

lovecreatesbeauty
 
V

Victor Bazarov

lovecreatesbeauty said:
I'm disturbed on this question on a long time. I think if I finally get
understand it with your kind help, I will get close to a excellent C++
programmer. And I only can rely on your expertise and help. I've read
some books, but no book focuses on this. Don't you think it is a very
important thing of C++ programming language? So your knowledge is of
great benefit to others, especially me.


1. Which (How many) members will be created automatically?

Scott Meyers seems to give this list in a early print of his
<<effective C++, 2nd>>, but he removed 1 (or 2, perhaps you know it),

Why don't you "know it"? Doesn't your nearby library have both books?
the list containing 6 members he gives is:

default constructor, copy constructor, destructor, assignment
operator, a pair of address-of operators (i.e. const, non-const) .

But in a later print (not a new edition, I don't read the 3rd one) he
removed the last pair of operators from that list without a detail
description, or he put that pair in that list before without a
thoroughly convinced reason. That is my complaint.

You should contact Scott, then. If it's a complaint, I mean. You know,
Scott is available on Internet...
Dr. Bjarne Stroustrup mentioned operator , (i.e. comma) is also a
predefined member (he mentioned total 3: =, &, and , in TC++PL sec
11.2.2), but Andrew Koenig said "That is not a member function." in my
post before. Obviously, it is inside a class body, so I do not
understand what he said.

What _who_ said? Koenig or Stroustrup?
Herb Sutter mentioned &&, || and , (comma) in his new book C++ coding
standard. But he did not give a complete list of automatically created
class members also. He always talks about some magic things on usage of
vector, list or some similar things with gurus. That is my complaint.

How about new and delete, and some others functions or operators which
I do not know the name. Who will give a complete list?

The complete list is conditional. For example, if you have any
parameterised c-tor, the default c-tor is not generated. Assignment op
is not generated if there are members that don't allow that...
2. Which (How many) members can not be inherited?

I know default ctor, copy ctor, dctor, assignment operator can not be
inherited. The first three members share the same name respectively
even the base class name and the derived class name are different - it
is obvious, but it helps me to understand the reason of non-inherited.
I can understand operator assignment will not be inherited also.

No constructors are inherited. Ever.

Virtualness of the destructor is an inherited trait.

The _copy_ assignment op is not inherited. Parameterized can be.
But I am not sure if there are other members also can not be inherited.

How about new and delete, and some others functions or operators which
I do not know the name. Who will give a complete list?

I don't think there is a complete and hard-set list. It's all relative.

V
 
T

TB

lovecreatesbeauty sade:
I'm disturbed on this question on a long time. I think if I finally get
understand it with your kind help, I will get close to a excellent C++
programmer. And I only can rely on your expertise and help. I've read
some books, but no book focuses on this. Don't you think it is a very
important thing of C++ programming language? So your knowledge is of
great benefit to others, especially me.

<snipped Scott Meyers>
<snipped Bjarne Stroustrup>
<snipped Andrew Koenig>
<snipped Herb Sutter>

Why not enter the next level and buy a copy of the standard?
ISBN: 0470846747
That way you won't need to flip through several books to
find hidden hints/answers about language features, just one.
 

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