Compile-Time Hex String Validation in Rust Using Const Evaluation
Learn how to leverage Rust's const evaluation features to validate hex strings at compile time, ensuring type safety and zero runtime overhead.
A deep dive into using Rust’s const evaluation features to validate hex strings at compile time, ensuring both correctness and zero runtime overhead.
Compile-time evaluation is a powerful feature in Rust that allows us to perform computations during compilation rather than at runtime. This can lead to better performance and earlier error detection. In this post, we’ll explore how to use Rust’s const evaluation features to validate hex strings at compile time, focusing on a practical example of validating Sui blockchain’s object IDs.
When working with blockchain or cryptographic systems, we often need to handle fixed-length hex strings that represent identifiers or addresses. For example, in the Sui blockchain, object IDs are 32-byte values typically represented as 64-character hex strings (with an optional “0x” prefix).
Working with these hex strings presents several challenges. First, we need to validate that the string has exactly 64 characters after any prefix. Second, we must ensure that all characters are valid hexadecimal digits (0-9, a-f, A-F). Third, we want to perform these validations with zero runtime overhead. Finally, we need to provide helpful compile-time error messages when validation fails.
