Add return lvalue test (and fix corresponding bugs)

commit_hash:f776eaac24e9bbe1abac58a171d9895556c43dd8

2 files changed, 7 insertions, 2 deletions

diff --git a/library/cpp/threading/future/core/coroutine_traits.h b/library/cpp/threading/future/core/coroutine_traits.h
index 502c5f8eb60..b36362db28a 100644
--- a/library/cpp/threading/future/core/coroutine_traits.h
+++ b/library/cpp/threading/future/core/coroutine_traits.h
@@ -3,6 +3,7 @@
 #include <library/cpp/threading/future/future.h>
 
 #include <coroutine>
+#include <utility>
 
 template <typename... Args>
 struct std::coroutine_traits<NThreading::TFuture<void>, Args...> {
@@ -75,11 +76,12 @@ struct std::coroutine_traits<NThreading::TFuture<T>, Args...> {
             Y_ASSERT(success && "value already set");
         }
 
-        template <typename E> requires std::derived_from<E, std::exception>
+        template <typename E>
+        requires std::derived_from<std::remove_cvref_t<E>, std::exception>
         void return_value(E&& err) {
             // Allow co_return std::exception instances in order to avoid stack unwinding
             bool success = State_->TrySetException(
-                std::make_exception_ptr(std::move(err)),
+                std::make_exception_ptr(std::forward<E>(err)),
                 /* deferCallbacks */ true
             );
             Y_ASSERT(success && "value already set");
diff --git a/library/cpp/threading/future/ut_gtest/coroutine_traits_ut.cpp b/library/cpp/threading/future/ut_gtest/coroutine_traits_ut.cpp
index 75de1d1c7fe..a9b0176920e 100644
--- a/library/cpp/threading/future/ut_gtest/coroutine_traits_ut.cpp
+++ b/library/cpp/threading/future/ut_gtest/coroutine_traits_ut.cpp
@@ -147,6 +147,9 @@ TEST(TestFutureTraits, ErrorViaReturnException) {
     auto coroutineReturnException = [&result]() -> NThreading::TFuture<size_t> {
         result.push_back("coroutine_return_exception");
         co_return std::runtime_error("exception_to_return");
+
+        static std::runtime_error another("another_exception_not_to_return");
+        co_return another;
     };
 
     auto coroutineReturnValueReturnException = [&]() -> NThreading::TFuture<size_t> {