google/quiver-dart — pull request #112 by seaneagan (2014-03-14 20:51:18+00:00)
Title: Add tuples

Could alternatively put these in a separate `quiver.tuples` library if desired.

Can also increase (or decrease) the maximum tuple length provided (I only need length = 2 right now :) ).

Looking to add this so I can use it to represent Map pairs:

```dart
Iterable pairs(Map map);
Map fromPairs(Iterable pairs);
```

And I'd also like to use it to replace `IndexedValue`:

```dart
Iterable> enumerate(Iterable iterable);
Stream> enumerate(Stream stream);
```