From c7a0c83ed44ec793285ebab58a86b232d10b5082 Mon Sep 17 00:00:00 2001
From: neargye <neargye@gmail.com>
Date: Sat, 9 Oct 2021 02:40:44 +0300
Subject: [PATCH] constexpr_for not work on vs2017

---
 test/test.cpp       |  8 ++++++++
 test/test_flags.cpp | 10 +++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/test/test.cpp b/test/test.cpp
index dd8b54d..c595249 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -974,6 +974,12 @@ TEST_CASE("cmp_less") {
   }
 }
 
+#if defined(__clang__) && __clang_major__ >= 5 || defined(__GNUC__) && __GNUC__ >= 9 || defined(_MSC_VER) && _MSC_VER >= 1920
+#  define MAGIC_ENUM_SUPPORTED_CONSTEXPR_FOR 1
+#endif
+
+#if defined(MAGIC_ENUM_SUPPORTED_CONSTEXPR_FOR)
+
 // from https://artificial-mind.net/blog/2020/10/31/constexpr-for
 template <auto Start, auto End, auto Inc, class F>
 constexpr void constexpr_for(F&& f) {
@@ -995,3 +1001,5 @@ TEST_CASE("constexpr_for") {
     [[maybe_unused]] Foo<Numbers, magic_enum::enum_value<Numbers, i>()> bar{};
   });
 }
+
+#endif
diff --git a/test/test_flags.cpp b/test/test_flags.cpp
index f6be44c..5efcb9b 100644
--- a/test/test_flags.cpp
+++ b/test/test_flags.cpp
@@ -691,6 +691,12 @@ TEST_CASE("bitwise_operators") {
   }
 }
 
+#if defined(__clang__) && __clang_major__ >= 5 || defined(__GNUC__) && __GNUC__ >= 9 || defined(_MSC_VER) && _MSC_VER >= 1920
+#  define MAGIC_ENUM_SUPPORTED_CONSTEXPR_FOR 1
+#endif
+
+#if defined(MAGIC_ENUM_SUPPORTED_CONSTEXPR_FOR)
+
 // from https://artificial-mind.net/blog/2020/10/31/constexpr-for
 template <auto Start, auto End, auto Inc, class F>
 constexpr void constexpr_for(F&& f) {
@@ -707,4 +713,6 @@ TEST_CASE("constexpr_for") {
   constexpr_for<0, magic_enum::enum_count<Color>(), 1>([](auto i) {
     [[maybe_unused]] Foo<Color, magic_enum::enum_value<Color, i>()> bar{};
   });
-}
\ No newline at end of file
+}
+
+#endif