From 785ebfad2fff4fde55104258e52218b153c035a0 Mon Sep 17 00:00:00 2001
From: Arnaud Giersch <arnaud.giersch@univ-fcomte.fr>
Date: Fri, 5 Feb 2021 15:06:28 +0100
Subject: [PATCH] Add helper macro to declare enums with to_string.

---
 include/xbt/utility.hpp | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/include/xbt/utility.hpp b/include/xbt/utility.hpp
index 2a1541ac8a..9634819ed9 100644
--- a/include/xbt/utility.hpp
+++ b/include/xbt/utility.hpp
@@ -7,8 +7,23 @@
 #ifndef XBT_UTILITY_HPP
 #define XBT_UTILITY_HPP
 
-#include <tuple>
 #include <functional>
+#include <tuple>
+#include <xbt/base.h>
+
+/** @brief Helper macro to declare enum class
+ *
+ * Declares an enum class EnumType, and a function "const char* to_c_str(EnumType)" to retrieve a C-string description
+ * for each value.
+ */
+#define XBT_DECLARE_ENUM_CLASS(EnumType, ...)                                                                          \
+  enum class EnumType;                                                                                                 \
+  static constexpr char const* to_c_str(EnumType value)                                                                \
+  {                                                                                                                    \
+    constexpr std::array<const char*, _XBT_COUNT_ARGS(__VA_ARGS__)> names{{_XBT_STRINGIFY_ARGS(__VA_ARGS__)}};         \
+    return names[static_cast<int>(value)];                                                                             \
+  }                                                                                                                    \
+  enum class EnumType { __VA_ARGS__ } /* defined here to handle trailing semicolon */
 
 namespace simgrid {
 namespace xbt {
-- 
2.20.1