A TYPE STRONGER THAN THE SUM OF ITS COMPONENTS

Summary from the TLDR DevOps newsletter

Rust APIs can encode stronger invariants by turning individual enum variants into dedicated types instead of accepting broader string or path values. Wrapping std::path::Component variants in types such as NormalComponent and ParentDirComponent lets the compiler enforce properties like safe path joins and prevents callers from passing values containing .., absolute paths, or other invalid components.