Rust Systems Programming
This skill governs the construction of highly performant, memory-safe backend systems using idiomatic Rust. It strictly enforces the borrow checker, explicit lifetimes, and prohibits the excessive use of cloning or dynamic dispatch unless absolutely architecturally required.
When to Use
- Use when developing core backend libraries or microservices in Rust.
- Use when handling unmanaged memory, FFI, or critical path execution loops.
- NOT for rapid prototyping of unstructured scripts.
Core Process
Phase 1: Ownership & Borrowing
- Default to passing data by reference (
&Tor&mut T). - Do not blindly add
.clone()to appease the compiler. Resolve the ownership topology explicitly.
Phase 2: Error Handling & Saftey
- Never use
.unwrap()or.expect()in production code. Always use the?operator andResult<T, E>. - Use custom Error enums (via libraries like
thiserrororanyhow) to propagate context.
Phase 3: Zero-Cost Abstractions
- Prefer static dispatch (generics with trait bounds
impl Trait) over dynamic dispatch (Box<dyn Trait>) to avoid runtime vtable overhead, unless dealing with heterogeneous collections. - Isolate any
unsafeblocks into tiny, heavily audited, and explicitly documented modules.
Common Rationalizations
| Rationalization | Reality |
|---|---|
"The borrow checker is yelling, I'll just .clone() this massive string." |
Cloning is a runtime performance penalty. You must restructure the lifetime or borrowing topology instead of hiding it. |
"I'll use .unwrap() because this should never fail." |
"Should never fail" is an assumption that causes panics in production. All errors must be handled gracefully via Result. |
"I'll use Box<dyn Trait> everywhere for flexibility." |
Dynamic dispatch incurs a performance cost. Use generics (impl Trait) unless dynamic collections are required. |
Red Flags
- Heavy usage of
.clone()on non-Copytypes in performance-critical loops. - Instances of
.unwrap()outside of unit tests. - Broad usage of
unsafeblocks without detailed// SAFETY:explanatory comments.
Verification
Before finalizing the Rust module, verify:
-
cargo clippypasses with zero warnings. - No
.unwrap()or.expect()calls exist in the production source. -
unsafecode is strictly localized and commented.
Source: meyverick/agy-skills — distributed by TomeVault.