Together, zero-initialization and constant initialization are called static initialization; all other initialization is dynamic initialization. ) Otherwise, you could just write:. There is no padding between the first field and the start of the object. Member function declarations with the same name and the name parameter-type-list cannot be overloaded if any of them is a static member function declaration. If a class has an initializer list constructor, then it takes priority over other forms of construction. Objections initialization of class/struct and its member The order of initialization : the member variables are initialized before this class's constructor is called. It may be declared first and defined later. Side by Side Comparisons of classic C++ examples solved via C++ vs C++11 vs C++14 vs C++17; Singleton Design Pattern; Smart Pointers; Sorting; Special Member Functions; Standard Library Algorithms; static_assert; std::any; std::array; Changing all array elements at once; Checking size of the Array; Element access; Initializing an std::array. Static class member must be initialized in single translation unit i. Whether reference members occupy any storage is implementation-defined, but their storage duration is the same as that of the object in which they are members. Output variable initialization. The following code will illustrate the of static member initializing technique. This feature is intended to reduce the verbosity of code that frequently access the static members of a particular class (e. Static Keyword can be used with following, Static variable in functions; Static Class Objects; Static member Variable in class. Mastering Class Member Initialization You know initialization is imperative for high-performing applications, but class members refuse to follow the standard rules. Here is another way that uses the 2-element data constructor. Initialization on declaration in a class was only possible for static constants. The for loop allows us to repeat certain commands. C++11/C++14 New Features initializer_list Uniform initialization Type Inference (auto) and Range-based for loop The nullptr and strongly typed enumerations Static assertions and Constructor. But to call a member function, we need a object. Static initialization block Static initialization block is used to initialize class variables, which are defined with the static keyword. Here we will see how to initialize the private static member variables initialization in C++. Yes, you can distinguish static functions from nonstatic functions. 2p2 only applies to non-static data members, but this one is static. Therefore I can't suggest a way to implement it. It is even common for some C++ programmers to use the term method to refer specifically to a virtual member. The IP address shall be derived from status of input pins, like DIP switch. In this example , While initializing first element of the array we have not specified the price of book 1. As you have probably noticed, to access the static member, you use the scope operator, ::, when you refer to it through the name of the class. C++11/C++14 New Features initializer_list Uniform initialization Type Inference (auto) and Range-based for loop The nullptr and strongly typed enumerations Static assertions and Constructor. Boost libraries are intended to be widely useful, and usable across a broad spectrum of applications. From: yu kuai <> Subject [PATCH 2/7] drm/amdgpu: add function parameter description in 'amdgpu_device_set_cg_state' Date: Mon, 4 Nov 2019 21:27:21 +0800. In this c++ Object Oriented programming video tutorial, you will learn about the static variables or the static members. Today I thought I would present two slightly different approaches to class member initialization and see what people were doing out there. Re: Cannot Initialize Class Members inside Class Definition Posted 16 April 2009 - 07:25 PM you don't want to move the declaration of self into the constructor just the initialization. Static data members in C++; Can we access private data members of a class without using a member or a friend function? Zero Initialization in C++; Uniform Initialization in C++; Initialization of a multidimensional arrays in C/C++; Initialization of static variables in C; Implicit initialization of variables with 0 or 1 in C. I can think of ways to make it compile, but since don't understand exactly what you are testing, I don't know what the purpose of the ToH class is and why you have chosen to make the test() function static. A member initialization list follows a constructor's parameter list. Following are such cases: 1) When no Base class default constructor is present. 0 Fixed In: Visual Studio 2019 version 16. 2p2 only applies to non-static data members, but this one is static. I'd prefer to initialize test::_n in main(). This chapter will also present the C syntax and resulting assembly code generated by the Keil uVision compiler. Note: Inline function can never be static. A virtual function is a member function in base class that you expect to redefine in derived classes. Member functions can be declared static in C++. [ Note: In most cases this is the defining declaration of the variable, but the initializing declaration of a non-inline static data member ([class. const data member triggers. Uses of Initializer List in C++. Here is an example:. Defining external variables to be static provides an additional control on which functions can access them. Static data members and their initializers can access other static private and protected members of their class. So, we do't need to pass any pointer as argument. Would it be possible to initialize it without using constructors?. In this article, we'll take a look at static member functions and how they are supported by the Windows Runtime. BTW: If that puts any standard, this concept is not forbidden in Google C++. The C++ Standard (9. The initialization of b invokes the constructor. Together, zero-initialization and constant initialization are called static initialization; all other initialization is dynamic initialization. A member is made static by prefixing the member declaration with the keyword 'static'. Initializing class fields to default values class SomeClass { static boolean b; static byte by; static char c; static double d; static float f; static int i. Accessing a data member depends solely on the access control of that data member. Here, we are going to learn by a program how to count the created objects using static member function in C++? Submitted by IncludeHelp, on September 14, 2018 Static data member. Passing pointers to static member functions is C'ish. An early version of the non-static data member initializer paper deleted “static” from 7. You can't initialize static class members like you can static variables that, for example, you put in the middle of a function body. Write A C++ Program Using Inline Initialization In Constructor. The main thing to remember is that it's C++-style to use as little static data as possible, but most Unix C requires a lot of static data, as well as initializer functions that need to be explicitly called somehow by main. Static is a keyword in C++ used to give special characteristics to an element. This works just fine. Suggested syntax is: class MyClass { static initialized = f. A static member function can access only the names of static members, enumerators, and nested types of the class in which it is declared. function objects to be used both from C++ and python, and also have them to access both C++ and Python code. In this article, we’ll take a look at static member functions and how they are supported by the Windows Runtime. static”, N4659, Draft. Therefore, you could use a lambda expression instead of defining and then creating a new instance of a class that implements Comparator:. Without static initialization, a self-initializing routine foo() might look as follows:. There are two alternatives to using a constructor to initialize instance variables: initializer blocks and final methods. In the definition of a constructor of a class, member initializer list specifies the initializers for direct and virtual base subobjects and non-static data members. A static member function is, in many senses, just a plain old function. Re: Cannot Initialize Class Members inside Class Definition Posted 16 April 2009 - 07:25 PM you don't want to move the declaration of self into the constructor just the initialization. Going back to C++, the reason why in C++ you have to define static data members in a separate file is more related to the C++ compilation model than to limitations imposed by the linker or other tools used by the compiler. If the initialization of a non-inline variable (since C++17) is deferred to happen after the first statement of main/thread function, it happens before the first odr-use of any variable with static/thread storage duration defined in the same translation unit as the variable to be initialized. You can define as many static methods as you want in a. C++ strings, C strings, and string literals may all be concatenated together in any order. Pointers to members allow you to refer to nonstatic members of class objects. struct struct_name { Type member_function1(signature); Type member_function2(signature); }; Typically, member function names are distinct, but the name of a member function may be the same as another if their signatures differ. As many of the documents mentioned above point out, this is much needed. Storage Access Specifiers. Static member functions are useful when you want to associate an action to a class, but you don't need to associate that action with a particular object. Static member functions do not work on an object, so the this pointer is not needed. C++17 Inline Variables. A static member function cannot be declared with the keywords virtual, const, volatile, or const volatile. Explicit initialization with constructors (C++ only) A class object with a constructor must be explicitly initialized or have a default constructor. In the example only public static member functions were used. TypeScript will let you know that you have called this function with an unexpected number of parameters. When one of the objects changes the value of data member variables, the effect is visible to all the object of the class. Without static initialization, a self-initializing routine foo() might look as follows:. Unfortunately, the static class member must be initialized outside of the. Background. Initialization happens before any the statement execution of the constructor body. There are times when you want to have the fast callbacks of C++ in boost. Class templates and static variables: The rule for class templates is same as function templates Each instantiation of class template has its own copy of member static variables. In other words to create a string in C you create an array of chars and set each element in the array to a char value that makes up the string. This is a limitation because you may want to initialize several static data members in the same loop or algorithm, for example. Further assume that you are following "good programming practice" by putting the declarations and definitions for this class in its own files. This is called a static member, because it remains the same. One of the member variable is an array. As others have shown, initialization is usually done with the static member variable's definition. A non-static member function of class X may be called. In C++, a static member is shared by all objects of the class. To initialize we have to use the class name then scope. It must be initialized in a separate declaration, not in the class definition or in the constructor initialization list. FAQ: Why can't I initialize my static member data in my constructor's initialization list? FAQ: Why are classes with static data members getting linker errors? FAQ: Can I add = initializer; to the declaration of a class-scope static const data member? FAQ: What's the "static initialization order fiasco"? (this FAQ). Side by Side Comparisons of classic C++ examples solved via C++ vs C++11 vs C++14 vs C++17; Singleton Design Pattern; Smart Pointers; Sorting; Special Member Functions; Standard Library Algorithms; static_assert; std::any; std::array; Changing all array elements at once; Checking size of the Array; Element access; Initializing an std::array. The static keyword is only used with the declaration of a static member, inside the class definition, but not with the definition of that static member:. static member functions do not have this pointer. Initialize a static const member with a template argument I have a few lines that compile well on my system but don't compile on a colleagues system. However, that was no longer guaranteed as of the first C standard, because of tightening up of various rules related to type safety (and also explicitly allowing compiler implementers more flexibility in how arguments are passed to functions). A static member can be a private member,but a glibal object cannot. 1) With an exception for const int, a static class member variable (const or not) must be defined outside the class body and outside any function. The CLR does not support this, so how does VB. An example use of static initialization follows. Static initializers will murder your family But only if your family is code. But remember that a static member function does not go with any particular instance of a class; therefore you don’t need to specify an instance. Static class member must be initialized in single translation unit i. Finally, the object's interfaces are initialized (we will discuss. Do not reenter a function during the initialization of a static variable declaration. Write A C++ Program Using Inline Initialization In Constructor. A third concept is "initialization". "You cannot initialize the static data member in the class definition — that’s simply a blueprint for an object and initializing values for members are not allowed. According to the rule of static in C++, only static member function can access static data members. To pass a static member function in pthread_create(), type case it as above i. The function of initialization is automatically carried out by the use of a special member function called a constructor. The destructor for object thirdthird is called before the destructor for global object first, but after all other objects are destroyed. • A constructor is a special kind of class member function that is executed when an object of that class is instantiated • Constructors are typically used to initialize member variables of the class to appropriate default values, or to allow the user to easily initialize those member variables to whatever values are. But to call a member function, we need a object. We then define a member variable that is a pointer to the member function, a constructor that initializes it to null, a template member function (Init) to set the member variable to point to the correct implementation of the static member function (&Run_T) and a public member function implementation (siRun) with the same parameters and. At file scope, you use list initialization or an expression which may invoke a lambda. So you can't try to give them a value inside the class declaration in your header file. In this article we will discuss how to initialize a map with std::initialzer_list. A non-constexpr (and as of C++17 non-inline) static member is declared as part of a class definition, and that definition may appear in a header, included in many files. In case of member create function, Base class can be friend of Derived. Log4j will find the properties file and initialize itself. If any of those properties are used in the base class initialization logic (either directly or indirectly, through another overridden open member implementation), it may lead to incorrect behavior or a runtime failure. For the static variables, we have to initialize them after defining the class. From: yu kuai <> Subject [PATCH 2/7] drm/amdgpu: add function parameter description in 'amdgpu_device_set_cg_state' Date: Mon, 4 Nov 2019 21:27:21 +0800. - Static member functions are used to maintain a single copy of a class member function across various objects of the class. ) operator with the object of that class. 17] How do I prevent the "static initialization order fiasco" for my static data members? Just use the same technique just described , but this time use a static member function rather than a global function. Using fold expression to initialize static constexpr class data member doesn't compile. These methods are independent and can appear in any order in the file. Do not reenter a function during the initialization of a static variable declaration. A static member function is, in many senses, just a plain old function. See also: order of construction, destructor. Static Data Member, Static Member Function, Friendly Function, and Dynamic Memory Allocation Stay ahead with the world's most comprehensive technology and business learning platform. There are two alternatives to using a constructor to initialize instance variables: initializer blocks and final methods. Some interesting facts about static member functions in C++. However, a globally declared anonymous union must be explicitly. Brace-initialization is a uniform method for initializing data in C++11. The static declaration can be of template argument type or of any defined type. Imagine you declare a large array, possibly made of 100 or 300 members, you wouldn't start counting the number of members. I intended to create a class which only have static members and static functions. When a data member is declared as static, only one copy of the data is maintained for all objects of the class. Unnamed padding is inserted between fields to align fields. Specifies the function that creates an object's prototype. Often used to acquire resources. Indeed, by adding member initializers into a structure may render your previously working code non-compilable. Static C++ member variables are defined using the static keyword. This is a common problem for those who starts with C++. }), (until C++14) the braces around the nested initializer lists may be elided (omitted), in which case as many initializer clauses as necessary are used to initialize every member or element of the corresponding subaggregate, and the subsequent initializer clauses. Consider Listing 1. For the static variables, we have to initialize them after defining the class. Finding C++ static initialization order problems. You can only have one definition of a static member in a program. Since a local class may define static member functions, it is possible to define nested functions in C++ somewhat comparable to the way programming languages like Pascal allow nested functions to be defined. Below we have a simple code example, where we are creating an object of the class Cube and calling the member function getVolume():. A C++ function or C++ class with functions which operates on integers, float and double data types can be unified with a single template function or class with functions which is flexible enough to use all three data types. A Static class is always sealed since it cannot be inherited further. If the data member is something that is slow to copy, this has a performance penalty if you call this member function in the inner loop of a CPU-bound application. However, that was no longer guaranteed as of the first C standard, because of tightening up of various rules related to type safety (and also explicitly allowing compiler implementers more flexibility in how arguments are passed to functions). Creating a vector object without any initialization will create an empty vector with no elements i. data member by value — excellent choice if the function is a non-static member function, and if the data member can be copied relatively quickly, e. Therefore, you could use a lambda expression instead of defining and then creating a new instance of a class that implements Comparator:. In a program, if you use a class that has a static member variable, that member variable is initialize with the minimum value of its type. Most notably, when the value returned by a function is used to initialize an object. Log4j will find the properties file and initialize itself. For more information, see Member Access Control (C++). In lots of programming tutorials, information about classes will be saved for much later. A friend function is used for accessing the non-public members of a class. In the function main() a, b, and c are three objects of class number. Reason: Whenever we call a class non-static member function using class object then THIS pointer is also passed to the function as a parameter internally and this is why a non-static member function of a class know that on which class object it is being called in case of multiple objects creation of the class. C++17 Inline Variables. static members are special members whose memory is automatically allocated at compile time and it's scope is entire program but only visible in function which is defined. Constructors are trivial only if there are no virtual member functions of the class and no virtual base classes. there are two problems in this solution (1) Abstract class can not have object of it. How we can do with C++? At first, let's see how to initialize a normal static member in C++. Static member function can access only static members but non-static member function can access both static and non-static members. Whether reference members occupy any storage is implementation-defined, but their storage duration is the same as that of the object in which they are members. The static class member variables are initialized to zero. A member is made static by prefixing the member declaration with the keyword 'static'. In C++98, only static const members of integral types could be initialized in-class, and the initializer has to be a constant expression. With Non-Static Data Member Initialization (see my post about it here), we can now declare and initialize member variables in one place. static ThreadLocal _x = new ThreadLocal (() => 3); You then use _x’s Value property to get or set its thread-local value. I intended to create a class which only have static members and static functions. The difference is that you have to use a class name to call a static function. The storage and retrieval of information are critical operations of any computer system. CPA Exam Primer: Static Data Member, Static Member Function, Friendly Function, and Dynamic Memory Allocation Stay ahead with the world's most comprehensive technology and business learning platform. I do not think there are any drawbacks of using non static data members initialization. In a class you wrap it in a static function to work around object initialization order being undefined across multiple compilation units. As you can see, I am trying to initialize a static data member of class1 with a function call which returns another class's static data member. Recent projects are done by members of the team A fast GPU simulation tool, written in C++ and needing a good understanding of modelling techniques, GPUs and device drivers. In C++, static at global/namespace scope means the function/variable is only used in the translation unit where it is defined, not in other translation units. A static member function has the same signature as a C function! Then you cast the pointer to the object on which you want to invoke the member function to void* and pass it to the wrapper as an additional argument or via a global variable. This is because non-static members must belong to a class object, and static member functions have no class object to work with!. A derived class can redefine any member function of the base class. 17] How do I prevent the "static initialization order fiasco" for my static data members? Just use the same technique just described , but this time use a static member function rather than a global function. So, every time object created, "a" will become zero. So, we do’t need to pass any pointer as argument. In below example, we have a static variable b of int type and have initialize to 50, but inside static function the value of static variable b has been modified to 10. However, since C# is all about Object Oriented programming and thereby classes, we will look at a basic introduction to the most important features now. Pointers to members allow you to refer to nonstatic members of class objects. As many of the documents mentioned above point out, this is much needed. /// private SiteStructure() { // Initialize members, etc. Class templates and static variables: The rule for class templates is same as function templates Each instantiation of class template has its own copy of member static variables. 2,2) allows to specify constant-initializer for const integral or const enumeration static data members only. A static class can't be instantiated, so in other words, it will work more as a grouping of related members than an actual class. static ThreadLocal _x = new ThreadLocal (() => 3); You then use _x’s Value property to get or set its thread-local value. Because object third is static, it exists until program termination. Here you are trying to use a static function from a different translation unit (Main. There are a lot of different ways to initialize a singleton in C++11 in a thread safe way. Presents an easy method to control order of initialization for static objects C++ Static Initialization Order: A New Solution to an Old Problem A function may. Providing default values. The type double is not an integral type. Any function declarations are allowed, with additional syntax elements that are only available for non-static member functions: final and override specifiers, pure-specifiers, cv-qualifiers, ref-qualifiers, and member initialization lists. With Non-Static Data Member Initialization (see my post about it here), we can now declare and initialize member variables in one place. In this example , While initializing first element of the array we have not specified the price of book 1. I develop an app with ETH interface and static IP address based on the STM32F207 MCU. Static C++ member variables are defined using the static keyword. Class is a declaration and static is a storage class of an object. auto register extern static In this article, we will discuss the 'static' storage class and explain how to use static. Rvalue references are tricky, and. We can also see that the code calls the function __cxa_atexit with the parameters $_ZL12qstring_data and $_ZN7QStringD1Ev Which are respectively the address of the QString object, and a function pointer of the QString destructor. Initializing Instance Members. We knew the dimensions of the arrays we have used so far, because we could count the number of members of the array. Tip: If one dictionary can be shared among many class instances, often performance will improve. The initializations of C::p and C::q cause errors because y is an object of a class that is derived privately from C, and its members are not accessible to members of C. It is arguably one of the most important features from C++11 that developers should understand and use. Member function definition can be written inside or outside the definition of the class. Static Function Members. It's a little bit difficult. zero-initialization - Applied to static and thread-local variables before any other initialization. How to define and use Friend Function in C++:. Member method declarations with the same name and the name parameter-type-list cannot be overloaded if any of them is a static member function declaration. The storage and retrieval of information are critical operations of any computer system. What you need to do is simply to provide a definition for your static member variable:. This program describes and demonstrates Simple Program for Static Data and Member Function Using C++ Programming with sample output,definition,syntax. This operation is better served by a member function void set(int x, int y), instead of friend function. " Inside a critical region, native code must not call other JNI functions, or any system call that may cause the current thread to block and wait for another Java thread. how a "nonstatic member reference must be relative to a specific object" can be solved accessing different function I am trying to pass some function for testing, into a main() node as shown below. I do not think there are any drawbacks of using non static data members initialization. }), (until C++14) the braces around the nested initializer lists may be elided (omitted), in which case as many initializer clauses as necessary are used to initialize every member or element of the corresponding subaggregate, and the subsequent initializer clauses. There are a lot of different ways to initialize a singleton in C++11 in a thread safe way. ) So if you want a particular set of classes' static constructors to run, it's up to you to do something explicit to make that happen. js website doesn't work properly without JavaScript enabled. Copy Constructors and Assignment Operators _____ Introduction Unlike other object-oriented languages like Java, C++ has robust support for object deep-copying and assignment. In the example only public static member functions were used. 4: Make interfaces precisely and strongly typed Reason. Static class member must be initialized in single translation unit i. In this post, we are going to learn about the static data members and static member functions, how they declare, how they access with and without member functions? C++ static data member It is a variable which is declared with the static keyword, it is also known as class member, thus only single copy of the variable creates for all objects. So static and class are orthogonal. We must treat the code inside this pair of functions as running in a "critical region. A non-static member function of class X may be called. Whether reference members occupy any storage is implementation-defined, but their storage duration is the same as that of the object in which they are members. This class contains methods that must be implemented by different classes that have static data (class or local) that they need to initialize when XMLPlatformUtils::Initialize is invoked. 14: What's the "static initialization order fiasco"? 10. By allowing non-static data members of classes to be initialized in the same way as non-static local variables (which should be thought of as non-static data members of the function frame), C++ initialization becomes more consistent. I have a C++ class that contains a map as a member variable. Going back to C++, the reason why in C++ you have to define static data members in a separate file is more related to the C++ compilation model than to limitations imposed by the linker or other tools used by the compiler. Ok I tested this out and was able to compile it. If a static data member is of const integral or const enumeration type, you may specify a constant initializer in the static data member's declaration. They are available only inside the function in which they are defined (in this case function_1()). A static member function can access only the names of static members, enumerators, and nested types of the class in which it is declared. A virtual function is a member function in base class that you expect to redefine in derived classes. A derived class can redefine any member function of the base class. Second, static member functions can directly access other static members (variables or functions), but not non-static members. struct member assignment. Two special functions were defined for initializing and finalizing a module: _init and _fini. If a class has an initializer list constructor, then it takes priority over other forms of construction. So, we declared another member function 'setLength' as public which assigned a value 7 to the length. with, void * (*)( void *) But as static functions are not associated with any object and therefore compiler doesn’t pass this pointer to it. The static member obey the normal public/private specifier rule. It's a little bit difficult. Except for aggregate initialization, explicit initialization using a constructor is the only way to initialize non-static constant and reference class members. The static member variables in a class are shared by all the class objects as there is only one copy of them in the memory, regardless of the number of objects of the class. Here, we are going to learn by a program how to count the created objects using static member function in C++? Submitted by IncludeHelp, on September 14, 2018 Static data member. I think you are not initializing the static class member in the right way. I have a C++ class that contains a map as a member variable. An object declared as const or volatile is trying to call a member function that is not. They can be constant,reference,arrays,class type and so forth. _Tfunc is here not a regular function, but a member function. C++ doesn't have static constructors, as Java or C# does, so you usually have to initialize the static data members one by one (independently). static member functions do not have this pointer. A derived class can redefine any public member function of the base class. So static and class are orthogonal. Member initializer lists work both with fundamental types and members that are classes themselves. We must treat the code inside this pair of functions as running in a "critical region. C++ Static Members Introduction This article describes basic concepts of C++ Storage Access Specifiers. Sorry, but the discord. 2,2) allows to specify constant-initializer for const integral or const enumeration static data members only. The C++ Standard (9. Static variables can be initialized outside the member function or class definition. Going back to C++, the reason why in C++ you have to define static data members in a separate file is more related to the C++ compilation model than to limitations imposed by the linker or other tools used by the compiler. In Visual Studio 2015 and earlier, an aggregate is not allowed to have brace-or-equal initializers for non-static members. The static member obey the normal public/private specifier rule. In every non static member function, first argument is always the pointer to the object of its own class. It's equipped with an ESP32 module made by U-BLOX. C++11/C++14 New Features initializer_list Uniform initialization Type Inference (auto) and Range-based for loop The nullptr and strongly typed enumerations Static assertions and Constructor. Member method declarations with the same name and the name parameter-type-list cannot be overloaded if any of them is a static member function declaration. When you define a class you have the option to initialize member variables in the declaration or in the constructor. A static member function is, in many senses, just a plain old function. Static members of a class are not associated with the objects of the class: they are independent variables with static or thread (since C++11) storage duration or regular functions. For some reason a long list of examples follows, as well as a discussion on performance. (I believe it was mainly introduced for the benefit of C++/CLI - the old managed C++ compiler in vs2002/2003 had major issues surrounding DLL initialization. It can, however, have static data members, static member functions, and non-static non-virtual member functions. The for loop allows us to repeat certain commands. The object's class_init (GClassInitFunc) function is invoked afterwards to complete initialization of the class structure. Why can't I initialize my static member data in my constructor's initialization list? 10. Just as in C#, classes can have static members, and this is indicated with the static keyword. As we will see further, this limitation was removed in C++11 that allows initialization of non-statics in the class declaration. The static member variables in a class are shared by all the class objects as there is only one copy of them in the memory, regardless of the number of objects of the class. So I decided to initialize this static variable in a static method, which first calls the initialization of the DOM Parser environment. If no variable or function is odr-used from a given. Effectively, when the macro is expanded, the complete Node struct looks like this:. But when they are static, there is no ambiguity. Static Keyword can be used with following, Static variable in functions; Static Class Objects; Static member Variable in class. A class can allow non-member functions and other classes to access its own private data, by making them friends. Declare the member function const or volatile, or remove the restriction from the object. It can be used to initialize static class members and maybe as entry point to the application. Danny Kalev explains how to use the new brace-initialization notation, class member initializers, and initialization lists to write better and shorter code, without compromising code safety or efficiency.