coord/ops: add lshift

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;
+    }
+};
 
 
 ///////////////////////////////////////////////////////////////////////////////