Rust is a fast, memory-efficient, and statically typed programming language. Its many benefits are why it has been voted the most admired programming language of 2023 and 2024, according to annual Stack Overflow surveys of over 90,000 developers. Rust is also a great language for smart contract writing and many software engineers opt for using that language in their Web3 projects. While Solidity has long been the go-to language for developing contracts on Ethereum, Rust is rapidly gaining traction as a powerful alternative. Today, we’ll dive into its benefits and risks, and explore use cases of Rust in smart contract development.

The Birth and Evolution of Rust

It all started in 2006 when Graydon Hoare, an Australian programmer, at the time working at the Mozilla Research, started conceptualizing his personal project. His goal was to develop a language that would answer the memory management and allocation problems of C and C++. According to Wikipedia, Rust was “named after the group of fungi that are over-engineered for survival”. 

In 2009 Mozilla decided to back the project and sponsor it financially. 12 engineers were employed to continue the work with Hoare. The first stable release of version 1.0 happened six years later, on May 15, 2015. On February 8, 2021, the Rust Foundation was officially established by its five founding companies: AWS, Huawei, Google, Microsoft, and Mozilla. Later, on April 6, 2021, Google revealed in a blog post that Rust would be supported within the Android Open Source Project as an alternative to C/C++.

What is Rust used for today?

Beyond writing smart contracts, building dApps, and minting tokens, Rust is primarily used for enhancing performance, strengthening security, and managing memory effectively. Developers favor Rust for its ability to ensure memory and thread safety, reducing the number of bugs caught during compilation. Rust's comprehensive type system plays a significant role in this. It features an advanced and versatile type system that lets developers define types flexibly and control how related objects interact.

The benefits of using Rust in blockchain development projects

1. User-friendly and easy to code

Rust stands out for its simplicity and ease of coding, unlike some popular languages used in blockchain development. For instance, handling threads in C++ can be quite challenging, and dealing with dependencies can be a nightmare. Rust tackles these issues within the language itself.

With extensive libraries, versatile frameworks, and highly useful tools, Rust offers a cohesive ecosystem where all necessary information is readily available. This is largely thanks to Rust's thorough and meticulous documentation. Consequently, coding in Rust is incredibly straightforward, contributing to its status as a highly admired language.

2. Performance and efficiency

Rust is a systems programming language designed for speed and efficiency. It compiles directly to machine code, offering high performance comparable to C and C++. This efficiency is particularly beneficial for blockchain environments, where resources are often limited, and performance overhead can be costly. Rust's compilation to WebAssembly (Wasm) further enhances its suitability for smart contracts, providing fast execution and interoperability across different platforms. Also, in the space-limited world of blockchain, size matters. The Rust compiler plays a crucial role by reordering struct fields to minimize the size of each type. As a result, Rust data structures are often very compact, sometimes even more so than those in C.

3. Memory safety

Rust is known for its strong emphasis on memory safety without requiring a garbage collector. The language's ownership model ensures that memory leaks and other unsafe behaviors are caught at compile time, reducing the risk of runtime errors. This feature is crucial in smart contracts, where security vulnerabilities can lead to significant financial losses.

4. Concurrency and parallelism

Rust's modern concurrency model prevents data races, a common problem in concurrent programming. This model is essential for smart contracts that may need to handle multiple transactions simultaneously without compromising the system's integrity. Rust's thread safety guarantees help maintain the consistency and reliability of smart contract operations.

5. Growing ecosystem and tooling

The Rust ecosystem is robust and rapidly expanding. Tools like cargo (Rust's package manager) and rustup (the Rust toolchain installer) streamline the development process. Frameworks like Substrate provide a comprehensive environment for developing blockchain applications and smart contracts. The `ink!` language, specifically designed for writing smart contracts in Rust, further simplifies the development process by offering high-level abstractions.

Risks of using Rust in smart contracts development

1. Learning curve

Rust has a steep learning curve, especially for developers coming from dynamically typed languages like JavaScript or Python. Concepts like ownership, lifetimes, and borrowing can be challenging to master. This learning curve can slow down the development process, especially for teams new to Rust. Luckily, the ease of coding one gets once the language is mastered, is a great reward for efforts.

2. Complexity in smart contract development

While Rust provides powerful features, it can also introduce complexity. Writing smart contracts in Rust requires a deep understanding of both the language and the specific requirements of blockchain systems. The need for meticulous management of resources and strict type-checking can make development more complex compared to languages like Solidity. 

3. Limited resources and community support

Although growing, Rust's community and resources are still smaller compared to more established languages in the smart contract space. This can make finding solutions to specific problems or bugs more challenging. On the bright side, the Rust and blockchain communities are active and supportive, and resources are continually expanding.

Use cases of Rust in blockchain development

1. Solana

Solana, a proof-of-stake (PoS) blockchain, utilizes Rust for writing smart contracts. It competes strongly with Ethereum and hosts a wide array of blockchain-based web3 applications. Rust is effectively used to develop Solana dApps, smart contracts, and NFTs, showcasing its versatility and efficiency on the Solana blockchain.

2. Polkadot

Polkadot is built using the Substrate framework, which is written in Rust. This implies that Polkadot likely wouldn't exist in its current form without Rust. Rust also plays a crucial role in implementing Polkadot's core runtime, which executes smart contracts. Polkadot's vision of interoperability features parachains that run parallel to its main blockchain, and Rust is extensively used in developing these parachains.

3. Near Protocol

Rust is instrumental in building various tools for developing and interacting with Near Protocol, including wallets, compilers, and explorers. It is also used to create and write dApps and smart contracts on the platform.

4. Comit

Comit is a cross-blockchain network enabling trustless applications across blockchains like Bitcoin and Solana. Although cross-blockchain communication isn't new, Comit utilizes Rust to achieve this. Their GitHub repository features numerous projects, all developed using Rust.

Conclusion

Rust offers a compelling alternative for smart contract development, combining performance, safety, and a growing ecosystem. While there are challenges, such as a steep learning curve and complex development processes, the benefits often outweigh these drawbacks, particularly for applications requiring high performance and security.

As the blockchain industry continues to evolve, Rust's role in smart contract development is likely to grow, driven by its technical advantages and the increasing adoption of frameworks like Substrate. For developers looking to build robust and efficient smart contracts, exploring Rust can open up new possibilities and set the foundation for future innovations.