From 0e89adaa660e98225fd7acbc79935c4c31657c96 Mon Sep 17 00:00:00 2001
From: Alexey Ochapov <alexez@alexez.com>
Date: Tue, 22 Dec 2020 23:49:35 +0300
Subject: [PATCH] fix byte formatting with `FMT_COMPILE`, use `__cpp_lib_byte`
 macro

---
 include/fmt/format.h | 8 +++++++-
 test/format-test.cc  | 2 +-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/fmt/format.h b/include/fmt/format.h
index ceef2ef1..f5835d9d 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -2112,8 +2112,14 @@ FMT_CONSTEXPR OutputIt write(OutputIt out, T value) {
 }
 
 template <typename Char, typename OutputIt, typename T,
+#ifdef __cpp_lib_byte
+          FMT_ENABLE_IF(std::is_enum<T>::value &&
+                        !std::is_same<T, Char>::value &&
+                        !std::is_same<T, std::byte>::value)>
+#else
           FMT_ENABLE_IF(std::is_enum<T>::value &&
                         !std::is_same<T, Char>::value)>
+#endif
 FMT_CONSTEXPR OutputIt write(OutputIt out, T value) {
   return write<Char>(
       out, static_cast<typename std::underlying_type<T>::type>(value));
@@ -3562,7 +3568,7 @@ FMT_FORMAT_AS(Char*, const Char*);
 FMT_FORMAT_AS(std::basic_string<Char>, basic_string_view<Char>);
 FMT_FORMAT_AS(std::nullptr_t, const void*);
 FMT_FORMAT_AS(detail::std_string_view<Char>, basic_string_view<Char>);
-#if __cplusplus >= 201703L
+#ifdef __cpp_lib_byte
 FMT_FORMAT_AS(std::byte, unsigned);
 #endif
 
diff --git a/test/format-test.cc b/test/format-test.cc
index 81bc406f..e821e773 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -1762,7 +1762,7 @@ TEST(FormatTest, JoinArg) {
 #endif
 }
 
-#if __cplusplus >= 201703L
+#ifdef __cpp_lib_byte
 TEST(FormatTest, JoinBytes) {
   std::vector<std::byte> v = {std::byte(1), std::byte(2), std::byte(3)};
   EXPECT_EQ("1, 2, 3", fmt::format("{}", fmt::join(v, ", ")));