Does Java SE 8 have Pairs or Tuples?

Question

I am playing around with lazy functional operations in Java SE 8, and I want to map an index i to a pair / tuple (i, value[i]), then <

Answer 1

Eclipse Collections has Pair and all combinations of primitive/object Pairs (for all eight primitives).

The Tuples factory can create instances of Pair, and the PrimitiveTuples factory can be used to create all combinations of primitive/object pairs.

We added these before Java 8 was released. They were useful to implement key/value Iterators for our primitive maps, which we also support in all primitive/object combinations.

If you're willing to add the extra library overhead, you can use Stuart's accepted solution and collect the results into a primitive IntList to avoid boxing. We added new methods in Eclipse Collections 9.0 to allow for Int/Long/Double collections to be created from Int/Long/Double Streams.

IntList list = IntLists.mutable.withAll(intStream);

Note: I am a committer for Eclipse Collections.