Remove TODO

include/fmt/core.h

@@ -788,7 +788,7 @@ template <typename Context> struct arg_mapper {
                 std::is_constructible<basic_string_view<char_type>, T>::value &&
                 !internal::is_string<T>::value)>
   FMT_CONSTEXPR basic_string_view<char_type> map(const T& val) {
-    return basic_string_view<char_type>(val);  // TODO: move to to_string_view
+    return basic_string_view<char_type>(val);
   }
   FMT_CONSTEXPR const char* map(const signed char* val) {
     static_assert(std::is_same<char_type, char>::value, "invalid string type");