Demacrify UTF-8 check

Author: vitaut

include/fmt/base.h

@@ -429,21 +429,20 @@ struct is_std_string_like<T, void_t<decltype(std::declval<T>().find_first_of(
     : std::is_convertible<decltype(std::declval<T>().data()),
                           const typename T::value_type*> {};
 
-// Returns true iff the literal encoding is UTF-8.
-constexpr auto is_utf8_enabled() -> bool { return "\u00A7"[1] == '\xA7'; }
-// It is a macro for better debug codegen without if constexpr.
-#define FMT_USE_UTF8 (!FMT_MSC_VERSION || fmt::detail::is_utf8_enabled())
-
-template <typename T> constexpr const char* narrow(const T*) { return nullptr; }
-constexpr FMT_ALWAYS_INLINE const char* narrow(const char* s) { return s; }
+// Check if the literal encoding is UTF-8.
+enum { is_utf8_enabled = "\u00A7"[1] == '\xA7' };
+enum { use_utf8 = !FMT_MSC_VERSION || is_utf8_enabled };
 
 #ifndef FMT_UNICODE
 #  define FMT_UNICODE 1
 #endif
 
-static_assert(!FMT_UNICODE || FMT_USE_UTF8,
+static_assert(!FMT_UNICODE || use_utf8,
               "Unicode support requires compiling with /utf-8");
 
+template <typename T> constexpr const char* narrow(const T*) { return nullptr; }
+constexpr FMT_ALWAYS_INLINE const char* narrow(const char* s) { return s; }
+
 template <typename Char>
 FMT_CONSTEXPR auto compare(const Char* s1, const Char* s2, std::size_t n)
     -> int {
@@ -2931,7 +2930,8 @@ FMT_API void vprint_buffered(FILE* f, string_view fmt, format_args args);
 template <typename... T>
 FMT_INLINE void print(format_string<T...> fmt, T&&... args) {
   vargs<T...> va = {{args...}};
-  if (!FMT_USE_UTF8) return detail::vprint_mojibake(stdout, fmt.str, va, false);
+  if (!detail::use_utf8)
+    return detail::vprint_mojibake(stdout, fmt.str, va, false);
   return detail::is_locking<T...>() ? vprint_buffered(stdout, fmt.str, va)
                                     : vprint(fmt.str, va);
 }
@@ -2947,7 +2947,7 @@ FMT_INLINE void print(format_string<T...> fmt, T&&... args) {
 template <typename... T>
 FMT_INLINE void print(FILE* f, format_string<T...> fmt, T&&... args) {
   vargs<T...> va = {{args...}};
-  if (!FMT_USE_UTF8) return detail::vprint_mojibake(f, fmt.str, va, false);
+  if (!detail::use_utf8) return detail::vprint_mojibake(f, fmt.str, va, false);
   return detail::is_locking<T...>() ? vprint_buffered(f, fmt.str, va)
                                     : vprint(f, fmt.str, va);
 }
@@ -2957,8 +2957,8 @@ FMT_INLINE void print(FILE* f, format_string<T...> fmt, T&&... args) {
 template <typename... T>
 FMT_INLINE void println(FILE* f, format_string<T...> fmt, T&&... args) {
   vargs<T...> va = {{args...}};
-  return FMT_USE_UTF8 ? vprintln(f, fmt.str, va)
-                      : detail::vprint_mojibake(f, fmt.str, va, true);
+  return detail::use_utf8 ? vprintln(f, fmt.str, va)
+                          : detail::vprint_mojibake(f, fmt.str, va, true);
 }
 
 /// Formats `args` according to specifications in `fmt` and writes the output

include/fmt/chrono.h

@@ -353,7 +353,7 @@ void write_codecvt(codecvt_result<CodeUnit>& out, string_view in,
 template <typename OutputIt>
 auto write_encoded_tm_str(OutputIt out, string_view in, const std::locale& loc)
     -> OutputIt {
-  if (FMT_USE_UTF8 && loc != get_classic_locale()) {
+  if (detail::use_utf8 && loc != get_classic_locale()) {
     // char16_t and char32_t codecvts are broken in MSVC (linkage errors) and
     // gcc-4.
 #if FMT_MSC_VERSION != 0 ||  \
@@ -648,7 +648,7 @@ FMT_CONSTEXPR inline auto get_units() -> const char* {
   if (std::is_same<Period, std::pico>::value) return "ps";
   if (std::is_same<Period, std::nano>::value) return "ns";
   if (std::is_same<Period, std::micro>::value)
-    return FMT_USE_UTF8 ? "µs" : "us";
+    return detail::use_utf8 ? "µs" : "us";
   if (std::is_same<Period, std::milli>::value) return "ms";
   if (std::is_same<Period, std::centi>::value) return "cs";
   if (std::is_same<Period, std::deci>::value) return "ds";

include/fmt/format.h

@@ -1862,7 +1862,7 @@ auto find_escape(const Char* begin, const Char* end)
 
 inline auto find_escape(const char* begin, const char* end)
     -> find_escape_result<char> {
-  if (!FMT_USE_UTF8) return find_escape<char>(begin, end);
+  if (!detail::use_utf8) return find_escape<char>(begin, end);
   auto result = find_escape_result<char>{end, nullptr, 0};
   for_each_codepoint(string_view(begin, to_unsigned(end - begin)),
                      [&](uint32_t cp, string_view sv) {

include/fmt/ostream.h

@@ -142,7 +142,7 @@ inline void vprint(std::ostream& os, string_view fmt, format_args args) {
 FMT_EXPORT template <typename... T>
 void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
   fmt::vargs<T...> vargs = {{args...}};
-  if (FMT_USE_UTF8) return vprint(os, fmt.str, vargs);
+  if (detail::use_utf8) return vprint(os, fmt.str, vargs);
   auto buffer = memory_buffer();
   detail::vformat_to(buffer, fmt.str, vargs);
   detail::write_buffer(os, buffer);

include/fmt/xchar.h

@@ -118,7 +118,7 @@ template <> struct is_char<char32_t> : std::true_type {};
 
 #ifdef __cpp_char8_t
 template <>
-struct is_char<char8_t> : bool_constant<detail::is_utf8_enabled()> {};
+struct is_char<char8_t> : bool_constant<detail::is_utf8_enabled> {};
 #endif
 
 template <typename... T>

test/ranges-test.cc

@@ -560,7 +560,7 @@ TEST(ranges_test, escape) {
   EXPECT_EQ(fmt::format("{}", vec{"\x7f"}), "[\"\\x7f\"]");
   EXPECT_EQ(fmt::format("{}", vec{"n\xcc\x83"}), "[\"n\xcc\x83\"]");
 
-  if (FMT_USE_UTF8) {
+  if (fmt::detail::use_utf8) {
     EXPECT_EQ(fmt::format("{}", vec{"\xcd\xb8"}), "[\"\\u0378\"]");
     // Unassigned Unicode code points.
     EXPECT_EQ(fmt::format("{}", vec{"\xf0\xaa\x9b\x9e"}), "[\"\\U0002a6de\"]");

test/unicode-test.cc

@@ -15,7 +15,7 @@
 
 using testing::Contains;
 
-TEST(unicode_test, use_utf8) { EXPECT_TRUE(FMT_USE_UTF8); }
+TEST(unicode_test, use_utf8) { EXPECT_TRUE(fmt::detail::use_utf8); }
 
 TEST(unicode_test, legacy_locale) {
   auto loc = get_locale("be_BY.CP1251", "Belarusian_Belarus.1251");