From 172c6855479ac210e508880f4d32dc78c71a926e Mon Sep 17 00:00:00 2001
From: terik23 <neargye@gmail.com>
Date: Thu, 25 Jul 2019 00:37:59 +0500
Subject: [PATCH] improve name_impl, ostream_operators

---
 include/magic_enum.hpp | 16 ++++++++++------
 test/test.cpp          | 14 +++++++-------
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/include/magic_enum.hpp b/include/magic_enum.hpp
index cdf85c3..60e255b 100644
--- a/include/magic_enum.hpp
+++ b/include/magic_enum.hpp
@@ -147,11 +147,11 @@ template <typename E>
 inline constexpr auto strings_v = strings_impl<E>(range_v<E>);
 
 template <typename E>
-[[nodiscard]] constexpr std::string_view name_impl(int value) noexcept {
+[[nodiscard]] constexpr std::string_view name_impl(E value) noexcept {
   static_assert(std::is_enum_v<E>, "magic_enum::detail::name_impl requires enum type.");
   constexpr auto strings = strings_v<E>;
 
-  if (auto i = static_cast<std::size_t>((value - min_v<E>)); i < strings.size()) {
+  if (auto i = static_cast<std::size_t>((static_cast<int>(value) - min_v<E>)); i < strings.size()) {
     return strings[i];
   }
 
@@ -291,7 +291,7 @@ template <typename E, typename D = detail::enable_if_enum_t<E>>
 [[nodiscard]] constexpr std::optional<D> enum_cast(std::underlying_type_t<D> value) noexcept {
   static_assert(detail::check_enum_v<E, D>, "magic_enum::enum_cast requires enum type.");
 
-  if (detail::name_impl<D>(static_cast<int>(value)).empty()) {
+  if (detail::name_impl<D>(static_cast<D>(value)).empty()) {
     return std::nullopt; // Invalid value or out of range.
   }
 
@@ -349,7 +349,7 @@ template <typename E, typename D = detail::enable_if_enum_t<E>>
 [[nodiscard]] constexpr std::string_view enum_name(E value) noexcept {
   static_assert(detail::check_enum_v<E, D>, "magic_enum::enum_name requires enum type.");
 
-  return detail::name_impl<D>(static_cast<int>(value));
+  return detail::name_impl<D>(value);
 }
 
 // Obtains string enum name sequence.
@@ -378,10 +378,12 @@ template <class Char, class Traits, typename E, typename D = detail::enable_if_e
 std::basic_ostream<Char, Traits>& operator<<(std::basic_ostream<Char, Traits>& os, E value) {
   static_assert(detail::check_enum_v<E, D>, "magic_enum::ostream_operators::operator<< requires enum type.");
 
-  if (auto name = detail::name_impl<D>(static_cast<int>(value)); !name.empty()) {
+  if (auto name = detail::name_impl<D>(value); !name.empty()) {
     for (auto c : name) {
       os.put(c);
     }
+  } else {
+    os << static_cast<std::underlying_type_t<D>>(value);
   }
 
   return os;
@@ -392,10 +394,12 @@ std::basic_ostream<Char, Traits>& operator<<(std::basic_ostream<Char, Traits>& o
   static_assert(detail::check_enum_v<E, D>, "magic_enum::ostream_operators::operator<< requires enum type.");
 
   if (value.has_value()) {
-    if (auto name = detail::name_impl<D>(static_cast<int>(value.value())); !name.empty()) {
+    if (auto name = detail::name_impl<D>(value.value()); !name.empty()) {
       for (auto c : name) {
         os.put(c);
       }
+    } else {
+      os << static_cast<std::underlying_type_t<D>>(value.value());
     }
   }
 
diff --git a/test/test.cpp b/test/test.cpp
index 06c5b4a..8770816 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -33,7 +33,7 @@
 
 enum class Color { RED = -12, GREEN = 7, BLUE = 15 };
 
-enum class Numbers : char { one = 10, two = 20, three = 30, many = 127 };
+enum class Numbers : int { one = 10, two = 20, three = 30, many = 127 };
 
 enum Directions { Up = 85, Down = -42, Right = 120, Left = -120 };
 
@@ -302,25 +302,25 @@ TEST_CASE("ostream_operators") {
   test_ostream(Color::RED, "RED");
   test_ostream(Color::GREEN, "GREEN");
   test_ostream(Color::BLUE, "BLUE");
-  test_ostream(static_cast<Color>(0), "");
+  test_ostream(static_cast<Color>(0), "0");
 
   test_ostream(Numbers::one, "one");
   test_ostream(Numbers::two, "two");
   test_ostream(Numbers::three, "three");
-  test_ostream(Numbers::many, "");
-  test_ostream(static_cast<Numbers>(0), "");
+  test_ostream(Numbers::many, "127");
+  test_ostream(static_cast<Numbers>(0), "0");
 
   test_ostream(Directions::Up, "Up");
   test_ostream(Directions::Down, "Down");
   test_ostream(Directions::Right, "Right");
   test_ostream(Directions::Left, "Left");
-  test_ostream(static_cast<Directions>(0), "");
+  test_ostream(static_cast<Directions>(0), "0");
 
   test_ostream(number::one, "one");
   test_ostream(number::two, "two");
   test_ostream(number::three, "three");
-  test_ostream(number::four, "");
-  test_ostream(static_cast<number>(0), "");
+  test_ostream(number::four, "400");
+  test_ostream(static_cast<number>(0), "0");
 }
 
 TEST_CASE("bitwise_operators") {