std::shared_ptr is one of the smart pointers introduced in C++11. Unlike a simple pointer, it has an associated control block that keeps track of the reference count for the managed object. This reference count is shared among all the copies of the shared_ptr instances pointing to the same object, ensuring proper memory management and deletion.
Shared Pointer in C++
The shared_ptr of type T can be declared as:
std::shared_ptr ptr_name;
We can initialize the shared_ptr using the following methods:
1. Initialization using a New Pointer
std::shared_ptr ptr(new T());
std::shared_ptr ptr = std::make_shared();
2. Initialization using existing Pointer
shared_ptr ptr(already_existing_pointer);
shared_ptr ptr = make_shared(already_existing_pointer);
Following are some members associated with shared_ptr:
| Method | Description |
|---|---|
| reset() | Resets the std::shared_ptr to empty, releasing ownership of the managed object. |
| use_count() | Returns the current reference count, indicating how many std::shared_ptr instances share ownership. |
| unique() | Check if there is only one std::shared_ptr owning the object (reference count is 1). |
| get() | Returns a raw pointer to the managed object. Be cautious when using this method. |
| swap(shr_ptr2) | swaps the contents (ownership) of two std::shared_ptr instances. |
0x1365c20 A::show() A::show() 0x1365c20 0x1365c20 2 2 0 1 0x1365c20
Value 1: 42 Value 2: 24 shared pointer 1 and shared pointer 3 point to the same object. Value 2 (after swap): 42 Value 3 (after swap): 24 Both shared pointer 1 and shared pointer 2 are valid.
Linked List: 1 -> 2 -> 3 -> NULL Linked List after deleting 2: 1 -> 3 -> NULLLike Article -->
Prerequisite – Smart Pointers Smart Pointer is a pointer-wrapping stack-allocated object. Smart pointers, in plain terms, are classes that wrap a pointer, or scoped pointers. C++ libraries provide implementations of smart pointers in the following types: auto_ptrunique_ptrshared_ptrweak_ptr They all are declared in a memory header file( #include
7 min read Virtual destruction using shared_ptr in C++Prerequisite: shared_ptr, Virtual Destructor As we know, deleting a derived class object using a pointer to a base class that has non-virtual destructor results in undefined behavior. Thus, we make the base class destructor virtual so that the polymorphic objects are being deleted properly in the correct order (i.e. the reverse order of their creat
3 min read C++ Programming LanguageC++ is the most used and most popular programming language developed by Bjarne Stroustrup. C++ is a high-level and object-oriented programming language. This language allows developers to write clean and efficient code for large applications and software development, game development, and operating system programming. It is an expansion of the C pr
9 min read 7 ways to Initialize Vector in C++Vectors in C++, like Arrays, are one of the most extensively used entities and to initialize vectors in C++ is one of the most common issues that users face. One of the most commonly used methods for vector initialization is the Array style. But C++, along with this, provides several different methods to initialize a vector. In this post, we have l
6 min read 30 OOPs Interview Questions and Answers (2024) UpdatedObject-oriented programming, or OOPs, is a programming paradigm that implements the concept of objects in the program. It aims to provide an easier solution to real-world problems by implementing real-world entities such as inheritance, abstraction, polymorphism, etc. in programming. OOPs concept is widely used in many popular languages like Java,
15+ min read Top 50 C++ Project Ideas For Beginners & AdvancedC++ is one of the most popular programming languages widely used in the software industry for projects in different domains like games, operating systems, web browsers, DBMS, etc due to its fast speed, versatility, lower-level memory access, and many more. Many top companies like Microsoft, Google, Apple, Netflix, etc use C++ to develop their produ
15+ min read C++ Programming ExamplesWriting C++ programs yourself is the best way to learn the C++ language. C++ programs are also asked in the interviews. This article covers the top practice problems for basic C++ programs on topics like control flow, patterns, and functions to complex ones like pointers, arrays, and strings. C++ Tutorial C++ Recent Articles Topics: Basic Programs
9 min read C++ Interview Questions and Answers (2024)C++ - the must-known and all-time favourite programming language of coders. It is still relevant as it was in the mid-80s. As a general-purpose and object-oriented programming language is extensively employed mostly every time during coding. As a result, some job roles demand individuals be fluent in C++. It is utilized by top IT companies such as
15+ min read vector erase() and clear() in C++Prerequisite: Vector in C++ Vectors are the same as dynamic arrays with the ability to resize themselves automatically when an element is inserted or deleted, with their storage being handled automatically by the container. vector::clear() The clear() function is used to remove all the elements of the vector container, thus making it size 0. Syntax
6 min read Substring in C++The substring function is used for handling string operations like strcat(), append(), etc. It generates a new string with its value initialized to a copy of a sub-string of this object. In C++, the header file which is required for std::substr(), string functions is <string>. The substring function takes two values pos and len as an argument
8 min read 2D Vector In C++ With User Defined SizeA 2D vector is a vector of the vector. Like 2D arrays, we can declare and assign values to a 2D vector! Assuming you are familiar with a normal vector in C++, with the help of an example we demonstrate how a 2D vector differs from a normal vector below: C/C++ Code /* Vectors belong to a C++ library called STL so we need to import it first! */ #incl
8 min read Virtual Function in C++A virtual function (also known as virtual methods) is a member function that is declared within a base class and is re-defined (overridden) by a derived class. When you refer to a derived class object using a pointer or a reference to the base class, you can call a virtual function for that object and execute the derived class's version of the meth
6 min read Inheritance in C++The capability of a class to derive properties and characteristics from another class is called Inheritance. Inheritance is one of the most important features of Object Oriented Programming in C++. In this article, we will learn about inheritance in C++, its modes and types along with the information about how it affects different properties of the
15+ min read C++ PolymorphismThe word "polymorphism" means having many forms. In simple words, we can define polymorphism as the ability of a message to be displayed in more than one form. A real-life example of polymorphism is a person who at the same time can have different characteristics. A man at the same time is a father, a husband, and an employee. So the same person ex
7 min read C++ Classes and ObjectsIn C++, classes and objects are the basic building block that leads to Object-Oriented programming in C++. In this article, we will learn about C++ classes, objects, look at how they work and how to implement them in our C++ program. What is a Class in C++?A class is a user-defined data type, which holds its own data members and member functions, w
9 min read Decision Making in C (if , if..else, Nested if, if-else-if )The conditional statements (also known as decision control structures) such as if, if else, switch, etc. are used for decision-making purposes in C programs. They are also known as Decision-Making Statements and are used to evaluate one or more conditions and make the decision whether to execute a set of statements or not. These decision-making sta
11 min read C++ Data TypesAll variables use data type during declaration to restrict the type of data to be stored. Therefore, we can say that data types are used to tell the variables the type of data they can store. Whenever a variable is defined in C++, the compiler allocates some memory for that variable based on the data type with which it is declared. Every data type
10 min read Convert String to int in C++Converting a string to int is one of the most frequently encountered tasks in C++. As both string and int are not in the same object hierarchy, we cannot perform implicit or explicit type casting as we can do in case of double to int or float to int conversion. Conversion is mostly done so that we can convert numbers that are stored as strings. Exa
8 min read std::sort() in C++ STLWe have discussed qsort() in C. C++ STL provides a similar function sort that sorts a vector or array (items with random access) It generally takes two parameters, the first one being the point of the array/vector from where the sorting needs to begin and the second parameter being the length up to which we want the array/vector to get sorted. The
6 min read Priority Queue in C++ Standard Template Library (STL)A C++ priority queue is a type of container adapter, specifically designed such that the first element of the queue is either the greatest or the smallest of all elements in the queue, and elements are in non-increasing or non-decreasing order (hence we can see that each element of the queue has a priority
Vectors are the same as dynamic arrays with the ability to resize themselves automatically when an element is inserted or deleted, with their storage being handled automatically by the container. Vector elements are placed in contiguous storage so that they can be accessed and traversed using iterators. In vectors, data is inserted at the end. Inse
11 min read Set in C++ Standard Template Library (STL)Sets are a type of associative container in which each element has to be unique because the value of the element identifies it. The values are stored in a specific sorted order i.e. either ascending or descending. The std::set class is the part of C++ Standard Template Library (STL) and it is defined inside the <set> header file. Syntax: std:
7 min read Map in C++ Standard Template Library (STL)Maps are associative containers that store elements in a mapped fashion. Each element has a key value and a mapped value. No two mapped values can have the same key values. std::map is the class template for map containers and it is defined inside the <map> header file. Basic std::map Member FunctionsSome basic functions associated with std::
8 min read The C++ Standard Template Library (STL)The Standard Template Library (STL) is a set of C++ template classes to provide common programming data structures and functions such as lists, stacks, arrays, etc. It is a library of container classes, algorithms, and iterators. It is a generalized library and so, its components are parameterized. Working knowledge of template classes is a prerequ
5 min read Object Oriented Programming in C++Object-oriented programming - As the name suggests uses objects in programming. Object-oriented programming aims to implement real-world entities like inheritance, hiding, polymorphism, etc. in programming. The main aim of OOP is to bind together the data and the functions that operate on them so that no other part of the code can access this data
10 min read Operator Overloading in C++in C++, Operator overloading is a compile-time polymorphism. It is an idea of giving special meaning to an existing operator in C++ without changing its original meaning. In this article, we will further discuss about operator overloading in C++ with examples and see which operators we can or cannot overload in C++. C++ Operator OverloadingC++ has
8 min read Templates in C++ with ExamplesA template is a simple yet very powerful tool in C++. The simple idea is to pass the data type as a parameter so that we don't need to write the same code for different data types. For example, a software company may need to sort() for different data types. Rather than writing and maintaining multiple codes, we can write one sort() and pass the dat
10 min read Friend Class and Function in C++A friend class can access private and protected members of other classes in which it is declared as a friend. It is sometimes useful to allow a particular class to access private and protected members of other classes. For example, a LinkedList class may be allowed to access private members of Node. We can declare a friend class in C++ by using the
6 min read Constructors in C++Constructor in C++ is a special method that is invoked automatically at the time an object of a class is created. It is used to initialize the data members of new objects generally. The constructor in C++ has the same name as the class or structure. It constructs the values i.e. provides data for the object which is why it is known as a constructor
7 min read Bitwise Operators in CIn C, the following 6 operators are bitwise operators (also known as bit operators as they work at the bit-level). They are used to perform bitwise operations in C. The & (bitwise AND) in C takes two numbers as operands and does AND on every bit of two numbers. The result of AND is 1 only if both bits are 1. The | (bitwise OR) in C takes two n
7 min read Article Tags :