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    <p>In C++ there is many ways of expanding/unpacking tuple and apply those tuple elements to a variadic template function. Here is a small helper class which creates index array. It is used a lot in template metaprogramming:</p> <pre><code>// ------------- UTILITY--------------- template&lt;int...&gt; struct index_tuple{}; template&lt;int I, typename IndexTuple, typename... Types&gt; struct make_indexes_impl; template&lt;int I, int... Indexes, typename T, typename ... Types&gt; struct make_indexes_impl&lt;I, index_tuple&lt;Indexes...&gt;, T, Types...&gt; { typedef typename make_indexes_impl&lt;I + 1, index_tuple&lt;Indexes..., I&gt;, Types...&gt;::type type; }; template&lt;int I, int... Indexes&gt; struct make_indexes_impl&lt;I, index_tuple&lt;Indexes...&gt; &gt; { typedef index_tuple&lt;Indexes...&gt; type; }; template&lt;typename ... Types&gt; struct make_indexes : make_indexes_impl&lt;0, index_tuple&lt;&gt;, Types...&gt; {}; </code></pre> <p>Now the code which does the job is not that big:</p> <pre><code> // ----------UNPACK TUPLE AND APPLY TO FUNCTION --------- #include &lt;tuple&gt; #include &lt;iostream&gt; using namespace std; template&lt;class Ret, class... Args, int... Indexes &gt; Ret apply_helper( Ret (*pf)(Args...), index_tuple&lt; Indexes... &gt;, tuple&lt;Args...&gt;&amp;&amp; tup) { return pf( forward&lt;Args&gt;( get&lt;Indexes&gt;(tup))... ); } template&lt;class Ret, class ... Args&gt; Ret apply(Ret (*pf)(Args...), const tuple&lt;Args...&gt;&amp; tup) { return apply_helper(pf, typename make_indexes&lt;Args...&gt;::type(), tuple&lt;Args...&gt;(tup)); } template&lt;class Ret, class ... Args&gt; Ret apply(Ret (*pf)(Args...), tuple&lt;Args...&gt;&amp;&amp; tup) { return apply_helper(pf, typename make_indexes&lt;Args...&gt;::type(), forward&lt;tuple&lt;Args...&gt;&gt;(tup)); } </code></pre> <p>Test is shown bellow:</p> <pre><code>// --------------------- TEST ------------------ void one(int i, double d) { std::cout &lt;&lt; "function one(" &lt;&lt; i &lt;&lt; ", " &lt;&lt; d &lt;&lt; ");\n"; } int two(int i) { std::cout &lt;&lt; "function two(" &lt;&lt; i &lt;&lt; ");\n"; return i; } int main() { std::tuple&lt;int, double&gt; tup(23, 4.5); apply(one, tup); int d = apply(two, std::make_tuple(2)); return 0; } </code></pre> <p>I'm not big expert in other languages, but I guess that if these languages do not have such functionality in their menu, there is no way to do that. At least with C++ you can, and I think it is not so much complicated... </p>
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    1. POHow do I expand a tuple into variadic template function's arguments?
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