rust-core-stdlib-overview

A tour of the Rust standard library. This skill is a map, not a tutorial: it tells you which std module provides which capability, what the prelude auto-imports, how core / alloc / std are layered, and when to drop to no_std. Deep mechanics live in cross-referenced skills.

Cross-references: [[rust-impl-no-std]] [[rust-impl-concurrency]] [[rust-impl-channels]] [[rust-core-async-runtime]] [[rust-impl-async-tokio]]

When to use this skill

• User asks "is there a standard library type for X" or "do I need a crate for this"
• User asks "what does the prelude import", "what is std::prelude::v1"
• User asks "what is the difference between core, alloc, and std"
• User asks "how do I make my crate no_std" at the map level (mechanics live in rust-impl-no-std)
• User confused about which std::sync primitive to pick at the catalogue level
• User asks "which std::collections type should I use" at the catalogue level
• User asks "where is X in std" and you need the module location

For deep mechanics of any module (lock poisoning, async runtimes, lifetime rules of &Path), refer to the cross-referenced skills.