Debug ppc failure

include/fmt/format.h

@@ -1314,10 +1314,13 @@ struct float_info<T, enable_if_t<std::numeric_limits<T>::digits == 64 ||
   static const int exponent_bits = 15;
 };
 
+template <int> constexpr int check_digits();
+
 // A double-double floating point number.
 template <typename T>
-struct float_info<T, enable_if_t<std::numeric_limits<T>::digits >= 106 &&
-                                 !std::numeric_limits<T>::is_iec559>> {
+struct float_info<T, enable_if_t<!std::numeric_limits<T>::is_iec559 &&
+                                 !is_float128<T>::value>> {
+  static constexpr int check = check_digits<std::numeric_limits<T>::digits>();
   using carrier_uint = detail::uint128_t;
 };
 

test/format-impl-test.cc

@@ -385,10 +385,11 @@ template <> struct numeric_limits<double_double> {
 }  // namespace std
 
 TEST(format_impl_test, write_double_double) {
-  auto s = std::string();
-  fmt::detail::write<char>(std::back_inserter(s), double_double(42), {});
+  // TODO: restore
+  // auto s = std::string();
+  // fmt::detail::write<char>(std::back_inserter(s), double_double(42), {});
 #ifndef _MSC_VER  // MSVC has an issue with specializing is_floating_point.
-  EXPECT_EQ(s, "42");
+  // EXPECT_EQ(s, "42");
 #endif
 }