[OptionalReference] value_or() should not be callable with r-values

Detected by clang-tidy-19's `bugprone-return-const-ref-from-parameter`

include/fixed_containers/optional_reference.hpp

@@ -7,6 +7,7 @@
 #include <compare>
 #include <memory>
 #include <optional>
+#include <type_traits>
 
 namespace fixed_containers
 {
@@ -86,11 +87,13 @@ class OptionalReference
         return *val();
     }
 
-    [[nodiscard]] constexpr reference value_or(reference default_value) const&
+    template <class U>
+    [[nodiscard]] constexpr reference value_or(U&& default_value) const&
+        requires(std::is_lvalue_reference_v<U>)
     {
         if (!has_value())
         {
-            return default_value;
+            return std::forward<U>(default_value);
         }
 
         return *val();

test/optional_reference_test.cpp

@@ -97,6 +97,15 @@ TEST(OptionalReference, Value)
     }
 }
 
+namespace
+{
+template <typename T, typename Parameter>
+constexpr bool value_or_is_callable_with_rvalue()
+{
+    return requires(T instance) { instance.value_or(Parameter{}); };
+}
+}  // namespace
+
 TEST(OptionalReference, ValueOr)
 {
     {
@@ -118,6 +127,17 @@ TEST(OptionalReference, ValueOr)
         const int& result = val1.value_or(fallback_value);
         EXPECT_EQ(5, result);
     }
+    {
+        /*
+        constexpr int ENTRY_1 = 5;
+        const OptionalReference<const int> val1(ENTRY_1);
+        const int& result = val1.value_or(77);  // This should fail to compile
+        EXPECT_EQ(5, result);
+        */
+
+        static_assert(!value_or_is_callable_with_rvalue<OptionalReference<const int>, int>(),
+                      "`value_or() should not be callable with r-values");
+    }
 }
 
 TEST(OptionalReference, DereferenceOperator)