From 3e5c89f64324021550feb8b7a0d44b92a29e224b Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Fri, 4 May 2018 17:06:18 +1000
Subject: [PATCH] coord/ops: add lshift

---
 coord/ops.hpp | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/coord/ops.hpp b/coord/ops.hpp
index 7c7e9cb5..af3c447f 100644
--- a/coord/ops.hpp
+++ b/coord/ops.hpp
@@ -1426,7 +1426,23 @@ namespace util {
     {
         return rshift (k, num, K {fill});
     }
-}
+
+
+    template <
+        typename K,
+        typename = std::enable_if_t<
+            is_coord_v<K>
+        >
+    >
+    constexpr auto
+    lshift (const K k, const int places, typename K::value_type fill)
+    {
+        K res {};
+        std::copy_n (std::cbegin (k) + places, K::elements - places, std::begin (res));
+        std::fill_n (std::begin (res) + K::elements - places, places, fill);
+        return res;
+    }
+};
 
 
 ///////////////////////////////////////////////////////////////////////////////