Reduce the numer of ifdefs with an empty (u)int128_t fallback

include/fmt/core.h

@@ -195,14 +195,6 @@
 #  define FMT_USE_EXPERIMENTAL_STRING_VIEW
 #endif
 
-#ifdef FMT_USE_INT128
-// Do nothing.
-#elif defined(__SIZEOF_INT128__)
-#  define FMT_USE_INT128 1
-#else
-#  define FMT_USE_INT128 0
-#endif
-
 FMT_BEGIN_NAMESPACE
 
 // Implementations of enable_if_t and other types for pre-C++14 systems.
@@ -239,6 +231,20 @@ using std_string_view = std::experimental::basic_string_view<Char>;
 template <typename T> struct std_string_view {};
 #endif
 
+#ifdef FMT_USE_INT128
+// Do nothing.
+#elif defined(__SIZEOF_INT128__)
+#  define FMT_USE_INT128 1
+using int128_t = __int128_t;
+using uint128_t = __uint128_t;
+#else
+#  define FMT_USE_INT128 0
+#endif
+#if !FMT_USE_INT128
+struct int128_t {};
+struct uint128_t {};
+#endif
+
 // Casts nonnegative integer to unsigned.
 template <typename Int>
 FMT_CONSTEXPR typename std::make_unsigned<Int>::type to_unsigned(Int value) {
@@ -673,10 +679,8 @@ FMT_TYPE_CONSTANT(int, int_type);
 FMT_TYPE_CONSTANT(unsigned, uint_type);
 FMT_TYPE_CONSTANT(long long, long_long_type);
 FMT_TYPE_CONSTANT(unsigned long long, ulong_long_type);
-#if FMT_USE_INT128
+FMT_TYPE_CONSTANT(int128_t, int128_type);
-FMT_TYPE_CONSTANT(__int128_t, int128_type);
+FMT_TYPE_CONSTANT(uint128_t, uint128_type);
-FMT_TYPE_CONSTANT(__uint128_t, uint128_type);
-#endif
 FMT_TYPE_CONSTANT(bool, bool_type);
 FMT_TYPE_CONSTANT(Char, char_type);
 FMT_TYPE_CONSTANT(double, double_type);
@@ -716,10 +720,8 @@ template <typename Context> class value {
     unsigned uint_value;
     long long long_long_value;
     unsigned long long ulong_long_value;
-#if FMT_USE_INT128
+    int128_t int128_value;
-    __int128_t int128_value;
+    uint128_t uint128_value;
-    __uint128_t uint128_value;
-#endif
     bool bool_value;
     char_type char_value;
     double double_value;
@@ -734,10 +736,8 @@ template <typename Context> class value {
   FMT_CONSTEXPR value(unsigned val) : uint_value(val) {}
   value(long long val) : long_long_value(val) {}
   value(unsigned long long val) : ulong_long_value(val) {}
-#if FMT_USE_INT128
+  value(int128_t val) : int128_value(val) {}
-  value(__int128_t val) : int128_value(val) {}
+  value(uint128_t val) : uint128_value(val) {}
-  value(__uint128_t val) : uint128_value(val) {}
-#endif
   value(double val) : double_value(val) {}
   value(long double val) : long_double_value(val) {}
   value(bool val) : bool_value(val) {}
@@ -797,10 +797,8 @@ template <typename Context> struct arg_mapper {
   FMT_CONSTEXPR ulong_type map(unsigned long val) { return val; }
   FMT_CONSTEXPR long long map(long long val) { return val; }
   FMT_CONSTEXPR unsigned long long map(unsigned long long val) { return val; }
-#if FMT_USE_INT128
+  FMT_CONSTEXPR int128_t map(int128_t val) { return val; }
-  FMT_CONSTEXPR __int128_t map(__int128_t val) { return val; }
+  FMT_CONSTEXPR uint128_t map(uint128_t val) { return val; }
-  FMT_CONSTEXPR __uint128_t map(__uint128_t val) { return val; }
-#endif
   FMT_CONSTEXPR bool map(bool val) { return val; }
 
   template <typename T, FMT_ENABLE_IF(is_char<T>::value)>
@@ -966,6 +964,10 @@ FMT_CONSTEXPR auto visit_format_arg(Visitor&& vis,
     return vis(arg.value_.int128_value);
   case internal::uint128_type:
     return vis(arg.value_.uint128_value);
+#else
+  case internal::int128_type:
+  case internal::uint128_type:
+    break;
 #endif
   case internal::bool_type:
     return vis(arg.value_.bool_value);

include/fmt/format.h

@@ -636,20 +636,12 @@ FMT_CONSTEXPR bool is_negative(T) {
   return false;
 }
 
-#if FMT_USE_INT128
+// Smallest of uint32_t, uint64_t, uint128_t that is large enough to
-// Smallest of uint32_t, uint64_t, unsigned __int128 that is large enough to
 // represent all values of T.
 template <typename T>
 using uint32_or_64_or_128_t = conditional_t<
     std::numeric_limits<T>::digits <= 32, uint32_t,
-    conditional_t<std::numeric_limits<T>::digits <= 64, uint64_t, __uint128_t>>;
+    conditional_t<std::numeric_limits<T>::digits <= 64, uint64_t, uint128_t>>;
-#else
-// Smallest of uint32_t and uint64_t that is large enough to represent all
-// values of T.
-template <typename T>
-using uint32_or_64_or_128_t =
-    conditional_t<std::numeric_limits<T>::digits <= 32, uint32_t, uint64_t>;
-#endif
 
 // Static data is placed in this class template for the header-only config.
 template <typename T = void> struct FMT_EXTERN_TEMPLATE_API basic_data {
@@ -699,7 +691,7 @@ inline int count_digits(uint64_t n) {
 #endif
 
 #if FMT_USE_INT128
-inline int count_digits(__uint128_t n) {
+inline int count_digits(uint128_t n) {
   int count = 1;
   for (;;) {
     // Integer division is slow so do it for a group of four digits instead
@@ -847,12 +839,8 @@ inline Char* format_decimal(Char* buffer, UInt value, int num_digits,
 template <typename Int> constexpr int digits10() noexcept {
   return std::numeric_limits<Int>::digits10;
 }
-
+template <> constexpr int digits10<int128_t>() noexcept { return 38; }
-#if FMT_USE_INT128
+template <> constexpr int digits10<uint128_t>() noexcept { return 38; }
-template <> constexpr int digits10<__int128_t>() noexcept { return 38; }
-
-template <> constexpr int digits10<__uint128_t>() noexcept { return 38; }
-#endif
 
 template <typename Char, typename UInt, typename Iterator, typename F>
 inline Iterator format_decimal(Iterator out, UInt value, int num_digits,
@@ -1644,15 +1632,14 @@ template <typename Range> class basic_writer {
   void write(int value) { write_decimal(value); }
   void write(long value) { write_decimal(value); }
   void write(long long value) { write_decimal(value); }
-#if FMT_USE_INT128
-  void write(__int128_t value) { write_decimal(value); }
-#endif
 
   void write(unsigned value) { write_decimal(value); }
   void write(unsigned long value) { write_decimal(value); }
   void write(unsigned long long value) { write_decimal(value); }
+
 #if FMT_USE_INT128
-  void write(__uint128_t value) { write_decimal(value); }
+  void write(int128_t value) { write_decimal(value); }
+  void write(uint128_t value) { write_decimal(value); }
 #endif
 
   // Writes a formatted integer.
@@ -1737,12 +1724,8 @@ template <typename Range> class basic_writer {
 using writer = basic_writer<buffer_range<char>>;
 
 template <typename T> struct is_integral : std::is_integral<T> {};
-
+template <> struct is_integral<int128_t> : std::true_type {};
-#if FMT_USE_INT128
+template <> struct is_integral<uint128_t> : std::true_type {};
-template <> struct is_integral<__int128_t> : std::true_type {};
-
-template <> struct is_integral<__uint128_t> : std::true_type {};
-#endif
 
 template <typename Range, typename ErrorHandler = internal::error_handler>
 class arg_formatter_base {

test/format-test.cc

@@ -1334,11 +1334,11 @@ TEST(FormatterTest, FormatBin) {
 }
 
 #if FMT_USE_INT128
-constexpr auto INT128_MAX = static_cast<__int128_t>(
+constexpr auto int128_max = static_cast<__int128_t>(
     (static_cast<__uint128_t>(1) << ((__SIZEOF_INT128__ * CHAR_BIT) - 1)) - 1);
-constexpr auto INT128_MIN = -INT128_MAX - 1;
+constexpr auto int128_min = -int128_max - 1;
 
-constexpr auto UINT128_MAX = ~static_cast<__uint128_t>(0);
+constexpr auto uint128_max = ~static_cast<__uint128_t>(0);
 #endif
 
 TEST(FormatterTest, FormatDec) {
@@ -1359,11 +1359,11 @@ TEST(FormatterTest, FormatDec) {
   EXPECT_EQ("18446744073709551616",
             format("{0}", static_cast<__int128_t>(UINT64_MAX) + 1));
   EXPECT_EQ("170141183460469231731687303715884105727",
-            format("{0}", INT128_MAX));
+            format("{0}", int128_max));
   EXPECT_EQ("-170141183460469231731687303715884105728",
-            format("{0}", INT128_MIN));
+            format("{0}", int128_min));
   EXPECT_EQ("340282366920938463463374607431768211455",
-            format("{0}", UINT128_MAX));
+            format("{0}", uint128_max));
 #endif
 
   char buffer[BUFFER_SIZE];
@@ -1399,9 +1399,9 @@ TEST(FormatterTest, FormatHex) {
             format("{0:x}", static_cast<__int128_t>(INT64_MIN) - 1));
   EXPECT_EQ("10000000000000000",
             format("{0:x}", static_cast<__int128_t>(UINT64_MAX) + 1));
-  EXPECT_EQ("7fffffffffffffffffffffffffffffff", format("{0:x}", INT128_MAX));
+  EXPECT_EQ("7fffffffffffffffffffffffffffffff", format("{0:x}", int128_max));
-  EXPECT_EQ("-80000000000000000000000000000000", format("{0:x}", INT128_MIN));
+  EXPECT_EQ("-80000000000000000000000000000000", format("{0:x}", int128_min));
-  EXPECT_EQ("ffffffffffffffffffffffffffffffff", format("{0:x}", UINT128_MAX));
+  EXPECT_EQ("ffffffffffffffffffffffffffffffff", format("{0:x}", uint128_max));
 #endif
 
   char buffer[BUFFER_SIZE];
@@ -1435,11 +1435,11 @@ TEST(FormatterTest, FormatOct) {
   EXPECT_EQ("2000000000000000000000",
             format("{0:o}", static_cast<__int128_t>(UINT64_MAX) + 1));
   EXPECT_EQ("1777777777777777777777777777777777777777777",
-            format("{0:o}", INT128_MAX));
+            format("{0:o}", int128_max));
   EXPECT_EQ("-2000000000000000000000000000000000000000000",
-            format("{0:o}", INT128_MIN));
+            format("{0:o}", int128_min));
   EXPECT_EQ("3777777777777777777777777777777777777777777",
-            format("{0:o}", UINT128_MAX));
+            format("{0:o}", uint128_max));
 #endif
 
   char buffer[BUFFER_SIZE];