Crate sorted_hlist

A minimal, no-std library for type-level heterogeneous lists (HLists) and their compile-time intersection.

You can build an HList via the mk_hlist! macro, mark lists as SortedHList when their element types are in non-decreasing order (via typenum::Cmp), and compute the intersection of two sorted lists using the Intersect trait (which under the hood uses IntersectUnchecked).

Macros

mk_hlist

Build a type-level HList from a comma-separated list of types.

Structs

HCons

A non-empty type-level list, with head of type H and tail T.

HNil

The empty type-level list.

Traits

HList

Marker trait for all HLists.

Intersect

Checked intersection of two sorted HLists.

IntersectByOrder

Internal dispatch by comparing the heads of two lists. Chooses one of three branches (Less, Equal, Greater) and recurses accordingly.

IntersectUnchecked

Compute the intersection of two arbitrary HLists, with no sortedness requirements. Yields an HList of the common elements (in the order of the left list).

LeOrEq

Internal helper trait indicating a type-level “leq” relationship for Cmp.

NonEmptyHList

Marker trait for non-empty HLists (i.e. HCons<_, _>).

SortedHList

Marker trait for lists whose element types are in non-decreasing order.