Workaround a double-double hexfloat format (#3366)

Signed-off-by: Vladislav Shchapov <[email protected]>
fmtlib · Apr 1, 2023 · 97aedea · 97aedea
1 parent bce8d4e
commit 97aedea
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Showing 2 changed files with 16 additions and 3 deletions.
diff --git a/include/fmt/format.h b/include/fmt/format.h
@@ -3344,7 +3344,7 @@ FMT_CONSTEXPR20 inline void format_dragon(basic_fp<uint128_t> value,
 }
 
 // Formats a floating-point number using the hexfloat format.
-template <typename Float>
+template <typename Float, FMT_ENABLE_IF(!is_double_double<Float>::value)>
 FMT_CONSTEXPR20 void format_hexfloat(Float value, int precision,
                                      float_specs specs, buffer<char>& buf) {
   // float is passed as double to reduce the number of instantiations and to
@@ -3425,6 +3425,12 @@ FMT_CONSTEXPR20 void format_hexfloat(Float value, int precision,
   format_decimal<char>(appender(buf), abs_e, detail::count_digits(abs_e));
 }
 
+template <typename Float, FMT_ENABLE_IF(is_double_double<Float>::value)>
+FMT_CONSTEXPR20 void format_hexfloat(Float value, int precision,
+                                     float_specs specs, buffer<char>& buf) {
+  format_hexfloat(static_cast<double>(value), precision, specs, buf);
+}
+
 template <typename Float>
 FMT_CONSTEXPR20 auto format_float(Float value, int precision, float_specs specs,
                                   buffer<char>& buf) -> int {

diff --git a/test/format-test.cc b/test/format-test.cc
@@ -1489,8 +1489,15 @@ TEST(format_test, format_long_double) {
   safe_sprintf(buffer, "%Le", 392.65l);
   EXPECT_EQ(buffer, fmt::format("{0:e}", 392.65l));
   EXPECT_EQ("+0000392.6", fmt::format("{0:+010.4g}", 392.64l));
-  safe_sprintf(buffer, "%La", 3.31l);
-  EXPECT_EQ(buffer, fmt::format("{:a}", 3.31l));
+
+  auto ld = 3.31l;
+  if (fmt::detail::is_double_double<decltype(ld)>::value) {
+    safe_sprintf(buffer, "%a", static_cast<double>(ld));
+    EXPECT_EQ(buffer, fmt::format("{:a}", ld));
+  } else {
+    safe_sprintf(buffer, "%La", ld);
+    EXPECT_EQ(buffer, fmt::format("{:a}", ld));
+  }
 }
 
 TEST(format_test, format_char) {