Merge branch 'fmtlib:master' into patch-1

include/fmt/core.h

@@ -314,6 +314,8 @@ template <typename T>
 using remove_cvref_t = typename std::remove_cv<remove_reference_t<T>>::type;
 template <typename T> struct type_identity { using type = T; };
 template <typename T> using type_identity_t = typename type_identity<T>::type;
+template <typename T>
+using underlying_t = typename std::underlying_type<T>::type;
 
 struct monostate {
   constexpr monostate() {}
@@ -1416,8 +1418,8 @@ template <typename Context> struct arg_mapper {
                 !has_fallback_formatter<T, char_type>::value)>
   FMT_CONSTEXPR FMT_INLINE auto map(const T& val)
       -> decltype(std::declval<arg_mapper>().map(
-          static_cast<typename std::underlying_type<T>::type>(val))) {
-    return map(static_cast<typename std::underlying_type<T>::type>(val));
+          static_cast<underlying_t<T>>(val))) {
+    return map(static_cast<underlying_t<T>>(val));
   }
 
   template <typename T, typename U = decltype(format_as(T())),
@@ -2214,13 +2216,12 @@ template <typename Char> constexpr bool is_ascii_letter(Char c) {
 
 // Converts a character to ASCII. Returns a number > 127 on conversion failure.
 template <typename Char, FMT_ENABLE_IF(std::is_integral<Char>::value)>
-constexpr auto to_ascii(Char value) -> Char {
-  return value;
+constexpr auto to_ascii(Char c) -> Char {
+  return c;
 }
 template <typename Char, FMT_ENABLE_IF(std::is_enum<Char>::value)>
-constexpr auto to_ascii(Char value) ->
-    typename std::underlying_type<Char>::type {
-  return value;
+constexpr auto to_ascii(Char c) -> underlying_t<Char> {
+  return c;
 }
 
 template <typename Char>

include/fmt/format-inl.h

@@ -2208,7 +2208,13 @@ FMT_HEADER_ONLY_CONSTEXPR20 int format_float(Float value, int precision,
 
   if (specs.fallback) return snprintf_float(value, precision, specs, buf);
 
-  if (!is_constant_evaluated() && precision < 0) {
+  int exp = 0;
+  bool use_dragon = true;
+  if (!is_fast_float<Float>()) {
+    // Use floor because 0.9 = 9e-1.
+    exp = static_cast<int>(std::floor(std::log10(value)));
+    if (fixed) adjust_precision(precision, exp + 1);
+  } else if (!is_constant_evaluated() && precision < 0) {
     // Use Dragonbox for the shortest format.
     if (specs.binary32) {
       auto dec = dragonbox::to_decimal(static_cast<float>(value));
@@ -2218,11 +2224,7 @@ FMT_HEADER_ONLY_CONSTEXPR20 int format_float(Float value, int precision,
     auto dec = dragonbox::to_decimal(static_cast<double>(value));
     write<char>(buffer_appender<char>(buf), dec.significand);
     return dec.exponent;
-  }
-
-  int exp = 0;
-  bool use_dragon = true;
-  if (is_fast_float<Float>()) {
+  } else {
     // Use Grisu + Dragon4 for the given precision:
     // https://www.cs.tufts.edu/~nr/cs257/archive/florian-loitsch/printf.pdf.
     const int min_exp = -60;  // alpha in Grisu.
@@ -2241,10 +2243,6 @@ FMT_HEADER_ONLY_CONSTEXPR20 int format_float(Float value, int precision,
       exp += handler.size - cached_exp10 - 1;
       precision = handler.precision;
     }
-  } else {
-    // Use floor because 0.9 = 9e-1.
-    exp = static_cast<int>(std::floor(std::log10(value)));
-    if (fixed) adjust_precision(precision, exp + 1);
   }
   if (use_dragon) {
     auto f = fp();

include/fmt/format.h

@@ -775,6 +775,7 @@ class basic_memory_buffer final : public detail::buffer<T> {
       // Set pointer to the inline array so that delete is not called
       // when deallocating.
       other.set(other.store_, 0);
+      other.clear();
     }
     this->resize(size);
   }
@@ -2354,8 +2355,7 @@ template <
             type::custom_type,
     FMT_ENABLE_IF(check)>
 FMT_CONSTEXPR auto write(OutputIt out, T value) -> OutputIt {
-  return write<Char>(
-      out, static_cast<typename std::underlying_type<T>::type>(value));
+  return write<Char>(out, static_cast<underlying_t<T>>(value));
 }
 
 template <typename Char, typename OutputIt, typename T,
@@ -2888,11 +2888,17 @@ template <typename T> auto ptr(const std::shared_ptr<T>& p) -> const void* {
   \endrst
  */
 template <typename Enum>
-constexpr auto underlying(Enum e) noexcept ->
-    typename std::underlying_type<Enum>::type {
-  return static_cast<typename std::underlying_type<Enum>::type>(e);
+constexpr auto underlying(Enum e) noexcept -> underlying_t<Enum> {
+  return static_cast<underlying_t<Enum>>(e);
 }
 
+namespace enums {
+template <typename Enum, FMT_ENABLE_IF(std::is_enum<Enum>::value)>
+constexpr auto format_as(Enum e) noexcept -> underlying_t<Enum> {
+  return static_cast<underlying_t<Enum>>(e);
+}
+}  // namespace enums
+
 #ifdef __cpp_lib_byte
 inline auto format_as(std::byte b) -> unsigned char { return underlying(b); }
 FMT_FORMAT_AS(std::byte, unsigned char);

test/format-test.cc

@@ -250,8 +250,9 @@ TEST(memory_buffer_test, move_ctor_dynamic_buffer) {
   buffer.push_back('a');
   basic_memory_buffer<char, 4, std_allocator> buffer2(std::move(buffer));
   // Move should rip the guts of the first buffer.
-  EXPECT_EQ(inline_buffer_ptr, &buffer[0]);
-  EXPECT_EQ("testa", std::string(&buffer2[0], buffer2.size()));
+  EXPECT_EQ(&buffer[0], inline_buffer_ptr);
+  EXPECT_EQ(buffer.size(), 0);
+  EXPECT_EQ(std::string(&buffer2[0], buffer2.size()), "testa");
   EXPECT_GT(buffer2.capacity(), 4u);
 }
 
@@ -948,8 +949,10 @@ TEST(format_test, precision) {
   EXPECT_THAT(outputs,
               testing::Contains(fmt::format("{:.838A}", -2.14001164E+38)));
 
-  auto ld = 8.43821965335442234493E-4933L;
-  EXPECT_EQ(fmt::format("{:.0}", ld), ld != 0 ? "8e-4933" : "0");
+  if (std::numeric_limits<long double>::digits == 64) {
+    auto ld = (std::numeric_limits<long double>::min)();
+    EXPECT_EQ(fmt::format("{:.0}", ld), "3e-4932");
+  }
 
   EXPECT_EQ("123.", fmt::format("{:#.0f}", 123.0));
   EXPECT_EQ("1.23", fmt::format("{:.02f}", 1.234));
@@ -1459,8 +1462,14 @@ TEST(format_test, write_uintptr_fallback) {
 
 enum class color { red, green, blue };
 
+namespace test_ns {
+enum class color { red, green, blue };
+using fmt::enums::format_as;
+}  // namespace test_ns
+
 TEST(format_test, format_enum_class) {
   EXPECT_EQ(fmt::format("{}", fmt::underlying(color::red)), "0");
+  EXPECT_EQ(fmt::format("{}", test_ns::color::red), "0");
 }
 
 TEST(format_test, format_string) {