From 44b60114a119bd27cb684525d6cdfca0f69855ed Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Mon, 7 Dec 2020 17:04:48 -0800
Subject: [PATCH] Add signum.

---
 src/advent/util.cr | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/advent/util.cr b/src/advent/util.cr
index e7337ae..bd82cfb 100644
--- a/src/advent/util.cr
+++ b/src/advent/util.cr
@@ -49,3 +49,10 @@ struct Tuple(*T)
     { self[0]//gcd, self[1]//gcd}
   end
 end
+
+struct Number
+  def signum
+    return 0 if self == 0
+    self // self.abs
+  end
+end