Minor cleanup

Author: vitaut

include/fmt/std.h

@@ -232,6 +232,19 @@ struct is_bit_reference_like<std::__bit_const_reference<C>> {
 };
 #endif
 
+template <typename T, typename Enable = void>
+struct has_format_as : std::false_type {};
+template <typename T>
+struct has_format_as<T, void_t<decltype(format_as(std::declval<const T&>()))>>
+    : std::true_type {};
+
+template <typename T, typename Enable = void>
+struct has_format_as_member : std::false_type {};
+template <typename T>
+struct has_format_as_member<
+    T, void_t<decltype(formatter<T>::format_as(std::declval<const T&>()))>>
+    : std::true_type {};
+
 }  // namespace detail
 
 template <typename T, typename Deleter>
@@ -678,25 +691,10 @@ template <typename T, typename Char> struct formatter<std::complex<T>, Char> {
   }
 };
 
-namespace detail {
-template <typename T, typename Enable = void>
-struct has_format_as : std::false_type {};
-template <typename T>
-struct has_format_as<T, void_t<decltype(format_as(std::declval<const T&>()))>>
-    : std::true_type {};
-
-template <typename T, typename Enable = void>
-struct has_format_as_member : std::false_type {};
-template <typename T>
-struct has_format_as_member<
-    T, void_t<decltype(formatter<T>::format_as(std::declval<const T&>()))>>
-    : std::true_type {};
-}  // namespace detail
-
-// Guard against format_as because reference_wrappers are implicitly convertible
-// to T&
 template <typename T, typename Char>
 struct formatter<std::reference_wrapper<T>, Char,
+                 // Guard against format_as because reference_wrapper is
+                 // implicitly convertible to T&.
                  enable_if_t<is_formattable<remove_cvref_t<T>, Char>::value &&
                              !detail::has_format_as<T>::value &&
                              !detail::has_format_as_member<T>::value>>

test/std-test.cc

@@ -413,37 +413,31 @@ TEST(std_test, format_shared_ptr) {
 
 TEST(std_test, format_reference_wrapper) {
   int num = 35;
-  EXPECT_EQ("35", fmt::to_string(std::cref(num)));
-  EXPECT_EQ("35", fmt::to_string(std::ref(num)));
-  EXPECT_EQ("35", fmt::format("{}", std::cref(num)));
-  EXPECT_EQ("35", fmt::format("{}", std::ref(num)));
+  EXPECT_EQ(fmt::to_string(std::cref(num)), "35");
+  EXPECT_EQ(fmt::to_string(std::ref(num)), "35");
+  EXPECT_EQ(fmt::format("{}", std::cref(num)), "35");
+  EXPECT_EQ(fmt::format("{}", std::ref(num)), "35");
 }
 
-// Regression test for https://github.com/fmtlib/fmt/issues/4424
-struct type_with_format_as {
-  int x;
-};
-
-int format_as(const type_with_format_as& t) { return t.x; }
+// Regression test for https://github.com/fmtlib/fmt/issues/4424.
+struct type_with_format_as {};
+int format_as(type_with_format_as) { return 20; }
 
 TEST(std_test, format_reference_wrapper_with_format_as) {
-  type_with_format_as t{20};
-  EXPECT_EQ("20", fmt::to_string(std::cref(t)));
-  EXPECT_EQ("20", fmt::to_string(std::ref(t)));
-  EXPECT_EQ("20", fmt::format("{}", std::cref(t)));
-  EXPECT_EQ("20", fmt::format("{}", std::ref(t)));
+  type_with_format_as t;
+  EXPECT_EQ(fmt::to_string(std::cref(t)), "20");
+  EXPECT_EQ(fmt::to_string(std::ref(t)), "20");
+  EXPECT_EQ(fmt::format("{}", std::cref(t)), "20");
+  EXPECT_EQ(fmt::format("{}", std::ref(t)), "20");
 }
 
-struct type_with_format_as_string {
-  std::string str;
-};
-
-std::string format_as(const type_with_format_as_string& t) { return t.str; }
+struct type_with_format_as_string {};
+std::string format_as(type_with_format_as_string) { return "foo"; }
 
 TEST(std_test, format_reference_wrapper_with_format_as_string) {
-  type_with_format_as_string t{"foo"};
-  EXPECT_EQ("foo", fmt::to_string(std::cref(t)));
-  EXPECT_EQ("foo", fmt::to_string(std::ref(t)));
-  EXPECT_EQ("foo", fmt::format("{}", std::cref(t)));
-  EXPECT_EQ("foo", fmt::format("{}", std::ref(t)));
+  type_with_format_as_string t;
+  EXPECT_EQ(fmt::to_string(std::cref(t)), "foo");
+  EXPECT_EQ(fmt::to_string(std::ref(t)), "foo");
+  EXPECT_EQ(fmt::format("{}", std::cref(t)), "foo");
+  EXPECT_EQ(fmt::format("{}", std::ref(t)), "foo");
 }