Disable is_streamable for string[_view]

fmtlib · Dec 9, 2021 · e4f0564 · e4f0564
1 parent 91533d3
commit e4f0564
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diff --git a/include/fmt/ostream.h b/include/fmt/ostream.h
@@ -45,6 +45,8 @@ struct is_streamable<
     enable_if_t<
         std::is_arithmetic<T>::value || std::is_array<T>::value ||
         std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_same<T, std::basic_string<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
         (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
     : std::false_type {};
 

diff --git a/test/ostream-test.cc b/test/ostream-test.cc
@@ -294,3 +294,8 @@ struct abstract {
 void format_abstract_compiles(const abstract& a) {
   fmt::format(FMT_COMPILE("{}"), a);
 }
+
+TEST(ostream_test, is_formattable) {
+  EXPECT_TRUE(fmt::is_formattable<std::string>());
+  EXPECT_TRUE(fmt::is_formattable<fmt::detail::std_string_view<char>>());
+}