empty class

Why is the size of an empty class not 0?This is necessary to ensure that two different objects have different addresses.The instantiation of a class is the allocation of an address in memory, with each instance having a unique two address in

Transferred from: http://blog.sina.com.cn/s/blog_93b45b0f01015s95.htmlWe often encounter these problems:(1) C + + defines an empty class, what is its size (sizeof)?(2) The size of a class that has only one char data member?(3) Can I define an empty

What is empty class and why worth Optimization Empty class is an empty class, such class empty {};Here, empty is obviously an empty class and has no members. However, empty classes are not limited to this form. For classes that only have member

[C ++ default function] The six class member functions generated by the empty class by default. The default Function1. default constructor.2. Default copy constructor.3. Default destructor.4. Default Value assignment operator. 5. default access

Link: http://blog.csdn.net/zhangxaochen/article/details/8032758 Here, "EMPTY class" is a class that does not mean anything or only contains non-virtual functions. In the past, I was only impressed that sizeof (empty class) would output "1", but I

A child boots went to an ideal international company for an interview the day before yesterday and came back to discuss the following question in the dormitory: In VC ++, there is an empty class that does not declare any member variables or

Beginners in the study of object-oriented programming language, more or less questions, we write the code and the final compiled code is very different, we do not know what the compiler does in the background to do the work. These are the reasons

Class A {};Class b{};Class C:public a{virtual void fun () = 0;};Class D:public B,public c{};Class A, B is obviously empty class, its size should be 0, why the compiler output is 1? This is the reason we have just described the instantiation (empty

Examples of file reading and writing in PythonWhen beginners are learning object-oriented programming languages, they are more or less doubtful that the code we write is quite different from the code that was compiled in the end, and we don't know

The story behind Javac--empty class Please indicate the original source and author information of the article and this statement in the form of a hyperlink. Http://www.blogbus.com/dreamhead-logs/5999838.html Programmers are most familiar with the

Today's interview is an interesting question: what is the amount of memory that an empty struct occupies in C + +? See the following code:#include struct s0{}; int Main () { sizeof S0 std::endl; return 0 ;}The interviewer alerted me on the

Today encountered a pen question, asked what is the size of the C + + empty class is what, with the program tested a bit.#include using namespace Std;class ClassA {};//struct STRUCTA {////};int main () { cout The output result is 1;Expands on how

C + + Primer Learning Notes _20_ class and Data Abstraction (6) _ Deep copy and shallow copy, empty class and empty array One, deep copy and shallow copyShallow copy: All variables of the copied object contain the same value as the original object,

classempty{ Public: Empty ();//default constructorEmpty (Constempty&);//copy Constructor~empty ();// DestructorsEmpty&operator=(Constempty&);//Assignment OperatorsEmpty*operator& ();//accessor operator Constempty*operator& ()Const;//accessor

// This is an empty test, only the test size Class {}; Class B {}; Class C: Public { Virtual void fun () = 0; }; Class D: Public B, public C {}; // Cout // Cout // Cout // Cout // The output result of the program execution is: // // Sizeof (A)

# Include Using namespace STD;Class A // A is an empty class. The compiler will mark this class with a char type and the size is 1.{ };Class B: public a // B inherits a, but it is also an empty class with the size of 1{ };Class C: VirtualPublic A //

A child Boots the day before yesterday to the ideal international company interview, came back in the dormitory discussed such a question: VC + +, there is an empty class, did not declare any member variables or functions, I would like to ask this

  This article mainly tests the class size, including empty classes, static and non-static variables, virtual and non-virtual single inheritance and multi-inheritance classes, and class or object   Test whether the virtual table and virtual pointer

I. Deep copy and light copy To put it simply, assume that a class has pointer members. If the memory to which the Pointer Points is also allocated during the copy, it is called Deep copy, for example (V2 is copied from V ): If only the memory of

Null class Default-generated members:Class Empty {};Empty (); Default constructorEmpty (const empty&); Default copy constructor~empty (); Default destructorempty& operator= (const empty&); Default assignment operatorempty* operator& (); Fetch