itertools

Extra iterator adaptors, iterator methods, free functions, and macros.

$cargo add itertools

Official docs outline

Extra Credit builds an outline of itertools's docs the first time your work uses it. Until then, start at the official documentation.

proc-macro2 A substitute implementation of the compiler's `proc_macro` API to decouple token-based libraries from the procedural macro use case.
base64 encodes and decodes base64 as bytes or utf8
windows-sys Rust for Windows
indexmap A hash table with consistent order and fast iteration.
thiserror-impl Implementation detail of the `thiserror` crate
thiserror derive(Error)
cfg-if A macro to ergonomically define an item depending on a large number of #[cfg] parameters. Structured like an if-else chain, the first matchi
memchr Provides extremely fast (uses SIMD on x86_64, aarch64 and wasm32) routines for 1, 2 or 3 byte search and single substring search.
regex-syntax A regular expression parser.
serde A generic serialization/deserialization framework
unicode-ident Determine whether characters have the XID_Start or XID_Continue properties according to Unicode Standard Annex #31
rand_chacha ChaCha random number generator