message: Fix dangling reference
diff: @@ -547,8 +547,8 @@ using caf_test_case_auto_fixture = caf::test::dummy_fixture;
  #define CAF_CHECK_FUNC(func, x_expr, y_expr) \
  do { \
  func comparator; \
  - const auto& x_val___ = x_expr; \
  - const auto& y_val___ = y_expr; \
  + auto&& x_val___ = x_expr; \
  + auto&& y_val___ = y_expr; \
  static_cast<void>(::caf::test::detail::check( \
  ::caf::test::engine::current_test(), __FILE__, __LINE__, \
  CAF_FUNC_EXPR(func, x_expr, y_expr), false, \
  @@ -587,8 +587,8 @@ using caf_test_case_auto_fixture = caf::test::dummy_fixture;
  #define CAF_REQUIRE_FUNC(func, x_expr, y_expr) \
  do { \
  func comparator; \
  - const auto& x_val___ = x_expr; \
  - const auto& y_val___ = y_expr; \
  + auto&& x_val___ = x_expr; \
  + auto&& y_val___ = y_expr; \
  auto CAF_UNIQUE(__result) = ::caf::test::detail::check( \
  ::caf::test::engine::current_test(), __FILE__, __LINE__, \
  CAF_FUNC_EXPR(func, x_expr, y_expr), false, \
  