While HPPC is not strictly modeled after Java Collections Framework (JCF), we did try to make the APIs look similar enough for comfortable use. One particular JCF feature not found in HPPC is collection views.

All HPPC classes come in two flavors: one for (almost) every primitive type and one generified for Objects.

Technically, the classes for primitives are automatically generated from the same template as the one for generics. For example, the list template KTypeArrayList generates the following (and other) classes:

• ObjectArrayList
• IntArrayList
• ByteArrayList

Not every combination makes sense and these are omitted (a list of booleans is technically identically a byte list; probably better represented by a bitset).

There is a diagram of classes and interfaces included in the JavaDocs of each release. See the class diagram for the current structure on the master branch.