From c7dbebe0df36ca83352dba28c6e0177008bf84ad Mon Sep 17 00:00:00 2001
From: RazvanN7 <razvan.nitu1305@gmail.com>
Date: Thu, 24 Aug 2017 10:05:30 +0300
Subject: [PATCH] Fix Issue 6004 - std.range.unzip()

---
 std/range/package.d | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/std/range/package.d b/std/range/package.d
index e50cc62cc..25a8806b9 100644
--- a/std/range/package.d
+++ b/std/range/package.d
@@ -6282,7 +6282,8 @@ FrontTransversal!(RangeOfRanges, opt) frontTransversal(
 
 /**
     Given a range of ranges, iterate transversally through the
-    `n`th element of each of the enclosed ranges.
+    `n`th element of each of the enclosed ranges. This function
+    is similar to `unzip` in other languages.
 
     Params:
         opt = Controls the assumptions the function makes about the lengths
@@ -6518,7 +6519,17 @@ Transversal!(RangeOfRanges, opt) transversal
     x[0] = [1, 2];
     x[1] = [3, 4];
     auto ror = transversal(x, 1);
-    assert(equal(ror, [ 2, 4 ][]));
+    assert(equal(ror, [ 2, 4 ]));
+}
+
+/// The following code does a full unzip
+@safe unittest
+{
+    import std.algorithm.comparison : equal;
+    import std.algorithm.iteration : map;
+    int[][] y = [[1, 2, 3], [4, 5, 6]];
+    auto z = y.front.walkLength.iota.map!(i => transversal(y, i));
+    assert(equal!equal(z, [[1, 4], [2, 5], [3, 6]]));
 }
 
 @safe unittest