Fix handling of enums in to_string (#2036)

fmtlib · Dec 3, 2020 · 33f9a6d · 33f9a6d
1 parent aabe0a8
commit 33f9a6d
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Showing 2 changed files with 11 additions and 0 deletions.
diff --git a/include/fmt/format.h b/include/fmt/format.h
@@ -2111,6 +2111,14 @@ FMT_CONSTEXPR OutputIt write(OutputIt out, T value) {
   return base_iterator(out, it);
 }
 
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_enum<T>::value &&
+                        !std::is_same<T, Char>::value)>
+FMT_CONSTEXPR OutputIt write(OutputIt out, T value) {
+  return write<Char>(
+      out, static_cast<typename std::underlying_type<T>::type>(value));
+}
+
 template <typename Char, typename OutputIt>
 constexpr OutputIt write(OutputIt out, bool value) {
   return write<Char>(out, string_view(value ? "true" : "false"));

diff --git a/test/format-test.cc b/test/format-test.cc
@@ -1987,6 +1987,9 @@ TEST(FormatTest, ToString) {
   EXPECT_EQ("42", fmt::to_string(42));
   EXPECT_EQ("0x1234", fmt::to_string(reinterpret_cast<void*>(0x1234)));
   EXPECT_EQ("foo", fmt::to_string(adl_test::fmt::detail::foo()));
+
+  enum test_enum : unsigned char { test_value };
+  EXPECT_EQ("0", fmt::to_string(test_value));
 }
 
 TEST(FormatTest, ToWString) { EXPECT_EQ(L"42", fmt::to_wstring(42)); }