C++Learn C++

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,

C++ Builder is the easiest and fastest C and C++ IDE for building simple or professional applications on the Windows, MacOS, iOS & Android operating systems. It is also easy for beginners to learn with its wide range of samples, tutorials, help files, and LSP support for code. RAD Studio’s C++ Builder version comes with the award-winning VCL framework for high-performance native Windows apps and the powerful FireMonkey (FMX) framework for cross-platform UIs.

There is a free C++ Builder Community Edition for students, beginners, and startups; it can be downloaded from here. For professional developers, there are Professional, Architect, or Enterprise versions of C++ Builder and there is a trial version you can download from here.

Oh hi there 👋
It’s nice to meet you.

Sign up to receive awesome C++ content in your inbox, every day.

We don’t spam! Read our privacy policy for more info.


Reduce development time and get to market faster with RAD Studio, Delphi, or C++Builder.
Design. Code. Compile. Deploy.
Start Free Trial

Free C++Builder Community Edition

About author

Dr. Yilmaz Yoru has 35+ years of coding with more than 30+ programming languages, mostly C++ on Windows, Android, Mac-OS, iOS, Linux, and some other operating systems. He graduated and received his MSc and PhD degrees from the Department of Mechanical Engineering of Eskisehir Osmangazi University. He is the founder and CEO of ESENJA LLC Company. His interests are Programming, Thermodynamics, Fluid Mechanics, Artificial Intelligence, 2D & 3D Designs, and high-end innovations.
Related posts
C++C++11C++14C++17C++20Introduction to C++Learn C++

Learn Copy Constructors in C++ Classes

C++C++11C++14C++17Introduction to C++Learn C++Syntax

Learn How To Use Types Of Destructors In C++?

C++C++11C++14Learn C++Syntax

How To Convert u32string To A wstring In C++

C++C++11C++14C++17C++20Introduction to C++Learn C++

How To Learn The Move Constructors In Modern C++?