Marcus Chen

The std::mem module provides utilities for working with memory: size_of, align_of, swap, replace, take, drop, forget, and transmute. I use mem::swap to exchange values without cloning, mem::replace to take a value out of a mutable reference, and mem::

MaybeUninit<T> is the safe way to work with uninitialized memory. It's useful for FFI, performance-critical code, or when you need to initialize large arrays element-by-element. Unlike uninitialized variables (which are UB), MaybeUninit is expli

cargo expand is a subcommand that shows the output of macro expansion. It's invaluable for debugging derive macros, understanding what declarative macros produce, or learning how async functions desugar. I run cargo expand --lib to see the entire crat

Procedural macros operate on Rust syntax trees, enabling custom #[derive(...)], attribute macros, or function-like macros. I write proc macros for boilerplate reduction: auto-generating builders, serialization, or validation. They're more powerful tha

A build.rs file runs before compiling your crate, enabling code generation, FFI binding generation, or environment checks. I use build scripts to generate Rust code from proto files (with prost), compile C libraries, or set cfg flags based on the targ

The tempfile crate creates temporary files and directories that are automatically cleaned up on drop. I use it in tests, build scripts, and anywhere I need scratch space. tempfile::NamedTempFile gives you a file path, while tempfile::tempfile() create