title: Tuple (unmodifiable ordered list of heterogeneous elements) support in Java
body: <p>I wonder why Java doesn't have a tuple data structure implementation in its standard library. For instance C++ has <a href="http://en.cppreference.com/w/cpp/utility/tuple" rel="noreferrer">a very good implementation</a> of this fixed-size collection of heterogeneous values. The same in <a href="https://hackage.haskell.org/package/base-4.8.1.0/docs/Data-Tuple.html" rel="noreferrer">Haskell</a>. In Java I only know <a href="http://www.javatuples.org/" rel="noreferrer">javatuples</a> and some support in <a href="https://github.com/functionaljava/functionaljava" rel="noreferrer">Functional Java</a> library via <code>Product</code> (<code>P1 - P8</code>) types. I wonder why <code>tuple</code> or at least <code>pair</code> not in standard library at all? Even Android SDK developers added their <a href="https://developer.android.com/reference/android/util/Pair.html" rel="noreferrer">own implementation</a> of 2-tuple (pair).</p>