Fix handling of _BitInt

include/fmt/base.h

@@ -417,22 +417,15 @@ template <typename T> auto convert_for_visit(T) -> monostate { return {}; }
 #  define FMT_USE_BITINT (FMT_CLANG_VERSION >= 1400)
 #endif
 
-template <typename T, int N = 0> struct bitint_traits {};
 #if FMT_USE_BITINT
 #  pragma clang diagnostic push
 #  pragma clang diagnostic ignored "-Wbit-int-extension"
-
-template <int N> struct bitint_traits<_BitInt(N)> {
-  static constexpr bool is_formattable = N <= 128;
-  using format_type = conditional_t<(N <= 64), long long, __int128>;
-};
-template <int N> struct bitint_traits<unsigned _BitInt(N)> {
-  static constexpr bool is_formattable = N <= 128;
-  using format_type =
-      conditional_t<(N <= 64), unsigned long long, unsigned __int128>;
-};
-
+template <int N> using bitint = _BitInt(N);
+template <int N> using ubitint = unsigned _BitInt(N);
 #  pragma clang diagnostic pop
+#else
+template <int N> struct bitint {};
+template <int N> struct ubitint {};
 #endif  // FMT_USE_BITINT
 
 // Casts a nonnegative integer to unsigned.
@@ -1170,12 +1163,20 @@ template <typename Char> struct arg_mapper {
   FMT_MAP_API auto map(double x) -> double { return x; }
   FMT_MAP_API auto map(long double x) -> long double { return x; }
 
-  template <typename T, FMT_ENABLE_IF(bitint_traits<T>::is_formattable)>
-  FMT_MAP_API auto map(T x) -> typename bitint_traits<T>::format_type {
+  template <int N, FMT_ENABLE_IF(N <= 64)>
+  FMT_MAP_API auto map(bitint<N> x) -> long long {
     return x;
   }
-  template <typename T, FMT_ENABLE_IF(!bitint_traits<T>::is_formattable)>
-  FMT_MAP_API auto map(T) -> unformattable {
+  template <int N, FMT_ENABLE_IF(N <= 64)>
+  FMT_MAP_API auto map(ubitint<N> x) -> unsigned long long {
+    return x;
+  }
+  template <int N, FMT_ENABLE_IF(N > 64)>
+  FMT_MAP_API auto map(bitint<N>) -> unformattable {
+    return {};
+  }
+  template <int N, FMT_ENABLE_IF(N > 64)>
+  FMT_MAP_API auto map(ubitint<N>) -> unformattable {
     return {};
   }
 

include/fmt/format.h

@@ -3973,10 +3973,11 @@ template <typename Char, typename Traits, typename Allocator>
 class formatter<std::basic_string<Char, Traits, Allocator>, Char>
     : public formatter<basic_string_view<Char>, Char> {};
 
-template <typename T, typename Char>
-struct formatter<T, Char,
-                 enable_if_t<(detail::bitint_traits<T>::is_formattable)>>
-    : formatter<typename detail::bitint_traits<T>::format_type, Char> {};
+template <int N, typename Char>
+struct formatter<detail::bitint<N>, Char> : formatter<long long, Char> {};
+template <int N, typename Char>
+struct formatter<detail::ubitint<N>, Char>
+    : formatter<unsigned long long, Char> {};
 
 /**
  * Converts `p` to `const void*` for pointer formatting.

test/format-test.cc

@@ -2518,59 +2518,36 @@ TEST(format_test, writer) {
 #if FMT_USE_BITINT
 #  pragma clang diagnostic ignored "-Wbit-int-extension"
 
-template <size_t N, bool is_signed>
-using bitint_helper =
-    fmt::conditional_t<is_signed, _BitInt(N), unsigned _BitInt(N)>;
-template <size_t N> using signed_bitint = bitint_helper<N, true>;
-template <size_t N> using unsigned_bitint = bitint_helper<N, false>;
-
 TEST(format_test, bitint) {
-  EXPECT_EQ(fmt::format("{}", unsigned_bitint<3>(7)), "7");
-  EXPECT_EQ(fmt::format("{}", signed_bitint<7>()), "0");
+  using fmt::detail::bitint;
+  using fmt::detail::ubitint;
+
+  EXPECT_EQ(fmt::format("{}", ubitint<3>(7)), "7");
+  EXPECT_EQ(fmt::format("{}", bitint<7>()), "0");
 
-  EXPECT_EQ(fmt::format("{}", unsigned_bitint<15>(31000)), "31000");
-  EXPECT_EQ(fmt::format("{}", signed_bitint<16>(INT16_MIN)), "-32768");
-  EXPECT_EQ(fmt::format("{}", signed_bitint<16>(INT16_MAX)), "32767");
+  EXPECT_EQ(fmt::format("{}", ubitint<15>(31000)), "31000");
+  EXPECT_EQ(fmt::format("{}", bitint<16>(INT16_MIN)), "-32768");
+  EXPECT_EQ(fmt::format("{}", bitint<16>(INT16_MAX)), "32767");
 
-  EXPECT_EQ(fmt::format("{}", unsigned_bitint<32>(4294967295)), "4294967295");
+  EXPECT_EQ(fmt::format("{}", ubitint<32>(4294967295)), "4294967295");
 
-  EXPECT_EQ(fmt::format("{}", unsigned_bitint<47>(140737488355327ULL)),
+  EXPECT_EQ(fmt::format("{}", ubitint<47>(140737488355327ULL)),
             "140737488355327");
-  EXPECT_EQ(fmt::format("{}", signed_bitint<47>(-40737488355327LL)),
+  EXPECT_EQ(fmt::format("{}", bitint<47>(-40737488355327LL)),
             "-40737488355327");
 
   // Check lvalues and const
-  auto a = signed_bitint<8>(0);
-  auto b = unsigned_bitint<32>(4294967295);
-  const auto c = signed_bitint<7>(0);
-  const auto d = unsigned_bitint<32>(4294967295);
+  auto a = bitint<8>(0);
+  auto b = ubitint<32>(4294967295);
+  const auto c = bitint<7>(0);
+  const auto d = ubitint<32>(4294967295);
   EXPECT_EQ(fmt::format("{}", a), "0");
   EXPECT_EQ(fmt::format("{}", b), "4294967295");
   EXPECT_EQ(fmt::format("{}", c), "0");
   EXPECT_EQ(fmt::format("{}", d), "4294967295");
 
-  static_assert(fmt::is_formattable<signed_bitint<64>, char>{}, "");
-  static_assert(fmt::is_formattable<unsigned_bitint<64>, char>{}, "");
-
-#  if FMT_USE_INT128
-  static_assert(fmt::is_formattable<signed_bitint<128>, char>{}, "");
-  static_assert(fmt::is_formattable<unsigned_bitint<128>, char>{}, "");
-
-  EXPECT_EQ(fmt::format("{}", signed_bitint<128>(0)), "0");
-  EXPECT_EQ(fmt::format("{}", unsigned_bitint<128>(0)), "0");
-  EXPECT_EQ("9223372036854775808",
-            fmt::format("{}", signed_bitint<65>(INT64_MAX) + 1));
-  EXPECT_EQ("-9223372036854775809",
-            fmt::format("{}", signed_bitint<65>(INT64_MIN) - 1));
-  EXPECT_EQ("18446744073709551616",
-            fmt::format("{}", unsigned_bitint<66>(UINT64_MAX) + 1));
-  EXPECT_EQ("170141183460469231731687303715884105727",
-            fmt::format("{}", signed_bitint<128>(int128_max)));
-  EXPECT_EQ("-170141183460469231731687303715884105728",
-            fmt::format("{}", signed_bitint<128>(int128_min)));
-  EXPECT_EQ("340282366920938463463374607431768211455",
-            fmt::format("{}", unsigned_bitint<128>(uint128_max)));
-#  endif
+  static_assert(fmt::is_formattable<bitint<64>, char>{}, "");
+  static_assert(fmt::is_formattable<ubitint<64>, char>{}, "");
 }
 #endif