Lib.rs

Meta: I have reviewed this package as part of a search for rectangle-packing algorithm implementations. I have not yet reviewed other packages, nor yet fully exercised this one. That said, my observations so far:

The code is straightforwardly written, and does not pose significant risks (other than correctness of the algorithm, which I have not evaluated). However, there are some caveats you may wish to consider.

• While no_std is supported, the code does require alloc and will allocate inside of its algorithms.

• Documentation is unclear. Broadly, it describes the purpose of items but fails to describe how to actually use or implement them, except in examples:

  • GroupedRectsToPlace does not explain what to do with the type parameters RectToPlaceId and GroupId.
  • In ComparePotentialContainersFn and contains_smallest_box(), what is a [WidthHeightDepth; 3]? Why are exactly three boxes being passed? The answer may be found in BinSection::try_place()'s documentation, but only by implication.
  • In BoxSizeHeuristicFn, why would one use anything other than volume_heuristic(), multiplying to obtain the volume?

• The type WidthHeightDepth is not public; this does not prevent the library from being used since its values are only ever provided, not consumed, but it is inelegant and potentially inconvenient since the requirement to provide a function accepting WidthHeightDepth can only be satisfied by a closure.

Comments on internal code quality, not relevant to usage:

• KeyValMap could be conditionally defined in one place as a type alias instead of twice in two modules.

• There are several pieces of unfinished, unused (but private) code.