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</pre><pre class="rust"><code><span class="doccomment">/// Converts an iterator of tuples into a tuple of containers.
///
/// `unzip()` consumes an entire iterator of n-ary tuples, producing `n` collections, one for each
/// column.
///
/// This function is, in some sense, the opposite of [`multizip`].
///
/// ```
/// use itertools::multiunzip;
///
/// let inputs = vec![(1, 2, 3), (4, 5, 6), (7, 8, 9)];
///
/// let (a, b, c): (Vec&lt;_&gt;, Vec&lt;_&gt;, Vec&lt;_&gt;) = multiunzip(inputs);
///
/// assert_eq!(a, vec![1, 4, 7]);
/// assert_eq!(b, vec![2, 5, 8]);
/// assert_eq!(c, vec![3, 6, 9]);
/// ```
///
/// [`multizip`]: crate::multizip
</span><span class="kw">pub fn </span>multiunzip&lt;FromI, I&gt;(i: I) -&gt; FromI
<span class="kw">where
</span>I: IntoIterator,
I::IntoIter: MultiUnzip&lt;FromI&gt;,
{
i.into_iter().multiunzip()
}
<span class="doccomment">/// An iterator that can be unzipped into multiple collections.
///
/// See [`.multiunzip()`](crate::Itertools::multiunzip) for more information.
</span><span class="kw">pub trait </span>MultiUnzip&lt;FromI&gt;: Iterator {
<span class="doccomment">/// Unzip this iterator into multiple collections.
</span><span class="kw">fn </span>multiunzip(<span class="self">self</span>) -&gt; FromI;
}
<span class="macro">macro_rules! </span>impl_unzip_iter {
($(<span class="macro-nonterminal">$T</span>:ident =&gt; <span class="macro-nonterminal">$FromT</span>:ident),<span class="kw-2">*</span>) =&gt; (
<span class="attribute">#[allow(non_snake_case)]
</span><span class="kw">impl</span>&lt;IT: Iterator&lt;Item = ($(<span class="macro-nonterminal">$T</span>,)<span class="kw-2">*</span>)&gt;, $(<span class="macro-nonterminal">$T</span>, <span class="macro-nonterminal">$FromT</span>: Default + Extend&lt;<span class="macro-nonterminal">$T</span>&gt;),* &gt; MultiUnzip&lt;($(<span class="macro-nonterminal">$FromT</span>,)<span class="kw-2">*</span>)&gt; <span class="kw">for </span>IT {
<span class="kw">fn </span>multiunzip(<span class="self">self</span>) -&gt; ($(<span class="macro-nonterminal">$FromT</span>,)<span class="kw-2">*</span>) {
<span class="comment">// This implementation mirrors the logic of Iterator::unzip resp. Extend for (A, B) as close as possible.
// Unfortunately a lot of the used api there is still unstable (https://github.com/rust-lang/rust/issues/72631).
//
// Iterator::unzip: https://doc.rust-lang.org/src/core/iter/traits/iterator.rs.html#2825-2865
// Extend for (A, B): https://doc.rust-lang.org/src/core/iter/traits/collect.rs.html#370-411
</span><span class="kw">let </span><span class="kw-2">mut </span>res = ($(<span class="macro-nonterminal">$FromT::default</span>(),)<span class="kw-2">*</span>);
<span class="kw">let </span>($(<span class="macro-nonterminal">$FromT</span>,)<span class="kw-2">*</span>) = <span class="kw-2">&amp;mut </span>res;
<span class="comment">// Still unstable #72631
// let (lower_bound, _) = self.size_hint();
// if lower_bound &gt; 0 {
// $($FromT.extend_reserve(lower_bound);)*
// }
</span><span class="self">self</span>.fold((), |(), ($(<span class="macro-nonterminal">$T</span>,)<span class="kw-2">*</span>)| {
<span class="comment">// Still unstable #72631
// $( $FromT.extend_one($T); )*
</span>$( <span class="macro-nonterminal">$FromT</span>.extend(std::iter::once(<span class="macro-nonterminal">$T</span>)); )*
});
res
}
}
);
}
<span class="macro">impl_unzip_iter!</span>();
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD, E =&gt; FromE);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD, E =&gt; FromE, F =&gt; FromF);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD, E =&gt; FromE, F =&gt; FromF, G =&gt; FromG);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD, E =&gt; FromE, F =&gt; FromF, G =&gt; FromG, H =&gt; FromH);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD, E =&gt; FromE, F =&gt; FromF, G =&gt; FromG, H =&gt; FromH, I =&gt; FromI);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD, E =&gt; FromE, F =&gt; FromF, G =&gt; FromG, H =&gt; FromH, I =&gt; FromI, J =&gt; FromJ);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD, E =&gt; FromE, F =&gt; FromF, G =&gt; FromG, H =&gt; FromH, I =&gt; FromI, J =&gt; FromJ, K =&gt; FromK);
<span class="macro">impl_unzip_iter!</span>(A =&gt; FromA, B =&gt; FromB, C =&gt; FromC, D =&gt; FromD, E =&gt; FromE, F =&gt; FromF, G =&gt; FromG, H =&gt; FromH, I =&gt; FromI, J =&gt; FromJ, K =&gt; FromK, L =&gt; FromL);
</code></pre></div>
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