...

1 files changed, 7 insertions, 4 deletions

diff --git a/include/cru/common/Format.hpp b/include/cru/common/Format.hpp
index c093c9e6..c2fd2e09 100644
--- a/include/cru/common/Format.hpp
+++ b/include/cru/common/Format.hpp
@@ -33,14 +33,17 @@ std::enable_if_t<std::is_floating_point_v<T>, String> ToString(T value) {
   return String(str.cbegin(), str.cend());
 }
 
-inline String ToString(String value) { return value; }
-
 template <typename T>
-String ToString(T&& value, StringView option) {
+std::enable_if_t<
+    std::is_convertible_v<decltype(ToString(std::declval<const T&>)), String>,
+    String>
+ToString(const T& value, StringView option) {
   CRU_UNUSED(option)
-  return ToString(std::forward<T>(value));
+  return ToString(value);
 }
 
+inline String ToString(String value) { return value; }
+
 namespace details {
 enum class FormatTokenType { PlaceHolder, Text };
 enum class FormatPlaceHolderType { None, Positioned, Named };