Rust for C-Programmers

15.7 Summary

Rust’s error-handling strategy is built upon ensuring you never accidentally overlook potential failures. Its key principles include:

• Recoverable vs. Unrecoverable Errors: Employ Result to handle issues that can be resolved and panic! for conditions that cannot be safely recovered.
• Option vs. Result: Use Option for a missing value without an error context, and Result when errors need to carry additional information.
• The ? Operator: Streamline error propagation without sacrificing clarity.
• Handling Diverse Error Types: Combine error variants through custom enums, trait objects, or conversion to unify error handling.
• Practical Guidelines: Return errors to the caller, provide actionable messages, and reserve unwrap or expect for truly impossible failure cases.

By systematically applying these principles, Rust code becomes more robust, safer, and clearer, avoiding the pitfalls often seen in C’s unchecked error returns.