From 283d9c519430fa3446844e6ddf7b2a77656e103e Mon Sep 17 00:00:00 2001
From: VladiMihaylenko <vxmihaylenko@gmail.com>
Date: Thu, 14 Mar 2019 14:00:24 +0300
Subject: [PATCH] Added default enum class hasher

---
 base/stl_helpers.hpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/base/stl_helpers.hpp b/base/stl_helpers.hpp
index cfd6632fc3..7257c9b836 100644
--- a/base/stl_helpers.hpp
+++ b/base/stl_helpers.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <algorithm>
+#include <cstdint>
 #include <functional>
 #include <initializer_list>
 #include <iterator>
@@ -414,4 +415,13 @@ void AccumulateIntervals1With2(Iter1 b1, Iter1 e1, Iter2 b2, Iter2 e2, InsertIte
   if (validPrev)
     *res++ = prev;
 }
+
+struct EnumClassHash
+{
+  template<typename T, std::enable_if_t<std::is_enum<T>::value> * = nullptr>
+  size_t operator()(T const & t) const noexcept
+  {
+    return static_cast<size_t>(t);
+  }
+};
 }  // namespace base