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Hunter Johnson for Educative

Posted on • Originally published at educative.io

Rust vs C++: an in-depth language comparison

Rust versus C++ is a recent trending topic for developers. There are many similarities between Rust and C++, and many developers wonder which is better to use (particularly for a systems programming language).

Both these languages compete in the realm of system-level development, and they both have steep learning curves compared to more beginner-friendly languages like Python.

When choosing a programming language, you should consider its efficiency and productivity for particular use cases. In this guide, we will take a deep dive into Rust and C++, comparing and contrasting these languages for their uses, pros, and cons.

This guide at a glance:

Rust

What is Rust?

Rust is a multi-paradigm programming language developed by Mozilla that has a focus on performance and safety. Rust is known for its advanced safe concurrency capabilities. Rust's syntax is similar to C++, but it offers faster speed and memory safety that doesn't use a garbage collector.

Rust was initially developed for the Mozilla Firefox browser, but its efficiency and advantages attracted many C++ developers who began to use Rust instead, commonly for game development.

Rust is innovative in terms of memory management. For example, it does not allow null or dangling pointers. Due to its functionality, Rust is commonly used to build device drivers, embedded systems, games, and operating systems such as BlogOS, Redox, RustOS, Rux, and Tock.

Rust code is arguably known best for its speed and ability to debug code before testing. For instance, Rust can help you develop programs that check for code errors at runtime.

Salient features of Rust

  • Memory management
  • Memory safety
  • Ownership system
  • Polymorphism
  • Speed and performance

Hello World in Rust:

fn main() {
println!("Hello World!");
}

-->
Hello World!
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C++

What is C++?

C++ is a high-level, general-purpose, compiled language that has been around for a while. Due to its complex syntax, C++ code is used for programs that require high-speed and concurrency. C++ is known for helping you get really close to the metal.

C++ is an extension of C, so it inherits many similarities but offers a bias toward embedded software and large systems.

It is known for its performance, robustness, and efficiency. C++ offers a lot of control over a system and its memory. C++ is the leading language for building operating systems like Microsoft Windows and for video game development, as several of the game development frameworks are in C++.

C++ also offers a rich standard library called the Standard Template Library. With it, it's easy to build everything from GUI apps to desktop apps, to 3D graphics and games.

Salient features of C++

  • Object-oriented
  • C++ Templates (STL)
  • Operator overloading
  • Inheritance
  • Lambda expressions

Hello World for C++:

#include <iostream>
using namespace std;

int main() {
  // your code goes here
  cout << "Hello World";
  return 0;
}

-->
Hello World
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Technical Comparison

So, why should you use Rust over C++ or the other way around? If both are high-performance, open source, and powerful, what's a better choice? Let's take a deep dive into their technical components.

At a high view, C++ has a larger community, wider use cases, and more frameworks, and is well recognized by any coding company. Rust, on the other hand, is better for safety, speed, and preventing incorrect/unsafe code due to its statically typed features.

Rust is great at preventing data races that can lead to undefined behavior, whereas C++ cannot do this work for you and opens up vulnerabilities.

Memory safety

Most system-level languages do not offer automatic memory management, as features like garbage collection can slow down performance. To keep its speed, C++ has sacrificed memory safety, which is a notable disadvantage.

Recent updates to C++ have had new features like RAII (Resource Acquisition is Initialization) to get rid of manual memory management, but they do not resolve the core issues under the hood.

To solve this issue, Rust uses a system of ownership, which enforces and improves its memory safety across the board. It essentially removes the need for any manual memory management procedures. Rust supplies the built-in features for management procedures while C++ leaves that to you.

Pointers

In computer science, a pointer is an object that stores a memory address. In other words, the address "points to" other data in the program. Smart pointers are data structures that have additional metadata and functionalities. Most high and low-level languages have some sort of pointer functionality.

C++ offers the types std::shared_ptr and std::unique_ptr that can be used like smart pointers. Rust has several smart pointers in its standard library, like the reference counting smart pointer type.

Both Rust and C++ use smart pointers a lot in the form of objects (String in Rust or std::string in C++) and offer a lot of useful additive features.

Compile Time

Full build times are about the same for C++ and Rust, depending on how many templates a C++ project is implementing (more templates will be slower). C++ generally does better with incremental compilation. Rust's compiler is known for being friendly. It offers useful error messages and top-notch tooling.

Ease of use

Most people who use both Rust and C++ say that Rust is easier to use due to its well-defined semantics and its ability to prevent unwanted/undefined behavior. Similarly, C++ has so many features that it can be challenging to keep track of. Since C++ shows you what's going on under the hood, C programmers need to understand it very well.

Frameworks and libraries

Though Rust is younger than C++, they both offer excellent frameworks and libraries, though C++ libraries tend to be a bit more general-purpose. The difference here is that C++ is not a framework-driven environment like Java, C#, or JavaScript, so they will not be commonly used.

In Rust, however, there are several frameworks that offer functional, secure, and robust code, for example:

  • Rocket: Rust web framework for improving security, speed, and flexibility.
  • Nickel: a Rust framework for developing user-friendly information flow control systems that have clear validation rules
  • Azul: a Rust-based immediate-mode GUI framework used for developing desktop applications

In terms of libraries, the main C++ library is the Standard Library, which is a collection of classes and functions. It provides several generic containers, functions for manipulating containers, generic strings and streams (including interactive and file I/O), and other language support.

The Unreal Engine is a framework written in C++ that is used for game development.

Game Development

Currently, C++ is the main language for game development. Most market-dominating games are written in C++, and the Unreal Engine, which is written in C++, is the main framework for game development. Unreal Engine is well-established, polished, and mature.

Rust is also entering the world of game development, but it does not offer the same power as frameworks. Games can be developed with Rust, but it will take some time before it can compete with C++ in this realm. As more Rust developers build out the Rust ecosystem, it may start to compete more heavily.

So, if you are interested in game development, keep learning C++, but keep a watchful eye on Rust, especially now with the creation of the Rust Foundation.

User Interface

UI development is a popular area of comparison for C++ and Rust, though neither language is the first-choice option for UI development. But how do they fare?

C++ offers GTKmm, which is a modern interface for the GTK+ C library. Rust offers Azul, an open-source, immediate-mode GUI framework that we mentioned above. It’s newer and more modern with an active community.

Conclusion and wrap up

So, which is better? Both programming languages have their unique advantages and disadvantages.

  • C++ is better in terms of community support. If you want a reliable, well-supported language with a powerful library, C++ is a good option. You should also use C++ for game development.
  • Rust is better for memory safety and concurrency. Rust is also easier to learn and use. If you want code to be very safe and avoid memory leaks, then Rust is the way to go.

At the end of the day, the language you choose depends on your comfortability. Choosing Rust or C++ will not fail you either way. Both are solid, well-used, recognized languages that will get the job done.

If you want to start learning either Rust or C++, check out Educative's courses to start your coding journey. Our The Ultimate Guide to Rust Programming is perfect for getting a solid hands-on foundation in Rust.

Our learning path C++ for Programmers is an ideal place for those who already know a bit about programming and want to tackle C++ head-on.

By the end of either course, you'll be comfortable building projects in Rust or C++ and take your programming to the next level.

Happy learning!

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