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What Is The Right Way To Use const_cast In C++?

What is casting in C++? What is a cast operator? What types of casting can be used in a C++ app? What is const_cast in C++? How can I use const_cast in C++?

C++ is a fast and powerful programming language suitable for manipulating data and memory for almost any purpose including operations with data types, operations with pointers, operations between classes, etc. In C++, both structs and classes can be used with const_cast operations.

In this post, we will explain how to use const_cast in C++. Before this, let’s remember what is casting in C++?

What is casting in C++?

Casting is a technique by which one data type to another data type. The operator used for this purpose is known as the cast operator. It is a unary operator which forces one data type to be converted into another data type. It takes on the format:

In C++, a cast operator is an Unary Operator which forces one data type to be converted into another data type.
In general, C++ supports four types of casting:

  1. Static Cast
  2. Dynamic Cast
  3. Const Cast
  4. Reinterpret Cast

What is Const Cast?

Constant Cast (const_cast) is a cast operator that converts between types with different cv-qualification.

Is there an example of how to use const_cast?

This is a simple example to the const_cast usage,

Note that here str should be initialized first to use const_cast othwerwise uninitialized str will adress a random place which may cause memory problems. So, if you are not sure it is exactly installed, the best thing is before using const_cast always check if it is addressing or null / empty. If you can’t you must be sure hundred percent it is adressed.

If we go on to this same example, here is the full and safe example to const_cast,

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About author

33+ years of coding with more than 30+ programming languages, mostly C++ on Windows, Android, Mac-OS, iOS, Linux and some other operating systems. Dr. Yilmaz Yoru was born in 1974, Eskisehir-Turkey. He graduated from the department of Mechanical Engineering of Eskisehir Osmangazi University in 1997. One year later he started to work in the same university as an assistant. He received his MSc and PhD degrees from the same department of the same university. He has married and he is a father of a son. Some of his interests are Programming, Thermodynamics, Fluid Mechanics and Artificial Intelligence. He also likes the graphical 2D & 3D design and high-end innovations.
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