From 2e927cd85dede4b09ed2da304847459e9f444880 Mon Sep 17 00:00:00 2001
From: John Wellbelove <jwellbelove@users.noreply.github.com>
Date: Fri, 12 Nov 2021 14:46:25 +0000
Subject: [PATCH] constexpr for enum_type

---
 include/etl/enum_type.h | 18 +++++++++---------
 test/test_enum_type.cpp | 27 ++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/include/etl/enum_type.h b/include/etl/enum_type.h
index caa43afe..23210a24 100644
--- a/include/etl/enum_type.h
+++ b/include/etl/enum_type.h
@@ -84,15 +84,15 @@ SOFTWARE.
 //*****************************************************************************
 #define ETL_DECLARE_ENUM_TYPE(TypeName, ValueType) \
   typedef ValueType value_type; \
-	TypeName() : value(static_cast<enum_type>(value_type())) {} \
-	TypeName(const TypeName &other) : value(other.value) {} \
-	TypeName(enum_type value_) : value(value_) {} \
-  TypeName& operator=(const TypeName &other) {value = other.value; return *this;} \
-  explicit TypeName(value_type value_) : value(static_cast<enum_type>(value_)) {} \
-	operator value_type() const {return static_cast<value_type>(value);} \
-  value_type get_value() const {return static_cast<value_type>(value);} \
-  enum_type get_enum() const {return value;} \
-  const char* c_str() const \
+	ETL_CONSTEXPR TypeName() : value(static_cast<enum_type>(value_type())) {} \
+	ETL_CONSTEXPR TypeName(const TypeName &other) : value(other.value) {} \
+	ETL_CONSTEXPR TypeName(enum_type value_) : value(value_) {} \
+  ETL_CONSTEXPR14 TypeName& operator=(const TypeName &other) {value = other.value; return *this;} \
+  ETL_CONSTEXPR explicit TypeName(value_type value_) : value(static_cast<enum_type>(value_)) {} \
+	ETL_CONSTEXPR operator value_type() const {return static_cast<value_type>(value);} \
+  ETL_CONSTEXPR value_type get_value() const {return static_cast<value_type>(value);} \
+  ETL_CONSTEXPR enum_type get_enum() const {return value;} \
+  ETL_CONSTEXPR14 const char* c_str() const \
   { \
     switch (value) \
     {
diff --git a/test/test_enum_type.cpp b/test/test_enum_type.cpp
index 49712a53..7e83e280 100644
--- a/test/test_enum_type.cpp
+++ b/test/test_enum_type.cpp
@@ -53,7 +53,7 @@ namespace
   SUITE(test_enum_type)
   {
     //*************************************************************************
-    TEST(Values)
+    TEST(test_values)
     {
       CHECK_EQUAL(0, enum_test::value_type(enum_test::ZERO));
       CHECK_EQUAL(1, enum_test::value_type(enum_test::ONE));
@@ -61,6 +61,31 @@ namespace
       CHECK_EQUAL(4, enum_test::value_type(enum_test::FOUR));
     }
 
+    //*************************************************************************
+    TEST(test_constexpr_values)
+    {
+      constexpr enum_test zero = enum_test::ZERO;
+      constexpr enum_test zero2(zero);
+      constexpr enum_test zero3 = zero;
+
+      constexpr int int_zero = zero;
+      constexpr int int_zero2 = zero.get_value();
+
+      constexpr enum_test enum_zero = zero;
+      constexpr enum_test enum_zero2 = zero.get_enum();
+
+      constexpr const char* string_zero = zero.c_str();
+
+      CHECK_EQUAL(0, zero.get_value());
+      CHECK_EQUAL(0, zero2.get_value());
+      CHECK_EQUAL(0, zero3.get_value());
+      CHECK_EQUAL(0, int_zero);
+      CHECK_EQUAL(0, int_zero2);
+      CHECK_EQUAL(0, enum_zero.get_value());
+      CHECK_EQUAL(0, enum_zero2.get_value());
+      CHECK_EQUAL(std::string("ZERO"), std::string(string_zero));
+    }
+
     //*************************************************************************
     TEST(test_c_str)
     {