diff --git a/runtime-light/coroutine/detail/when-any.h b/runtime-light/coroutine/detail/when-any.h
index 085c1f3200..f124f5928e 100644
--- a/runtime-light/coroutine/detail/when-any.h
+++ b/runtime-light/coroutine/detail/when-any.h
@@ -15,6 +15,7 @@
 #include "runtime-light/coroutine/concepts.h"
 #include "runtime-light/coroutine/type-traits.h"
 #include "runtime-light/coroutine/void-value.h"
+#include "runtime-light/metaprogramming/type-functions.h"
 #include "runtime-light/stdlib/diagnostics/logs.h"
 
 namespace kphp::coro::detail::when_any {
@@ -120,7 +121,10 @@ class when_any_ready_awaitable<std::tuple<task_types...>> {
 
       const auto task_result_processor{[&result = m_awaitable.m_result](auto&& task) noexcept {
         if (auto task_result{std::forward<decltype(task)>(task).result()}; !result.has_value() && task_result.has_value()) {
-          result = std::move(task_result);
+          using result_variant_type = std::remove_cvref<decltype(result)>::type::value_type;
+          using task_result_type = decltype(task_result)::value_type;
+          result =
+              result_variant_type{std::in_place_index<kphp::type_functions::variant_index<result_variant_type, task_result_type>()>, *std::move(task_result)};
         }
       }};
       std::apply([&task_result_processor](auto&&... tasks) noexcept { (std::invoke(task_result_processor, std::forward<decltype(tasks)>(tasks)), ...); },
@@ -290,8 +294,11 @@ class when_any_task {
 
 template<kphp::coro::concepts::awaitable awaitable_type>
 auto make_when_any_task(awaitable_type awaitable) noexcept -> when_any_task<typename kphp::coro::awaitable_traits<awaitable_type>::awaiter_return_type> {
-  co_yield co_await std::move(awaitable);
-  co_return;
+  if constexpr (std::is_void_v<typename kphp::coro::awaitable_traits<awaitable_type>::awaiter_return_type>) {
+    co_await std::move(awaitable);
+  } else {
+    co_yield co_await std::move(awaitable);
+  }
 }
 
 } // namespace kphp::coro::detail::when_any
diff --git a/runtime-light/coroutine/io-scheduler.h b/runtime-light/coroutine/io-scheduler.h
index 241c518014..657dae1539 100644
--- a/runtime-light/coroutine/io-scheduler.h
+++ b/runtime-light/coroutine/io-scheduler.h
@@ -16,6 +16,7 @@
 #include <memory>
 #include <optional>
 #include <ranges>
+#include <type_traits>
 #include <utility>
 #include <variant>
 
@@ -463,13 +464,24 @@ auto io_scheduler::schedule(coroutine_type coroutine, std::chrono::duration<rep_
   using expected_return_type = typename kphp::coro::coroutine_traits<coroutine_type>::return_type;
 
   if (timeout <= std::chrono::duration<rep_type, period_type>{0}) [[unlikely]] {
-    co_return std::expected<expected_return_type, timeout_status>{co_await schedule(std::move(coroutine))};
+    if constexpr (std::is_void_v<expected_return_type>) {
+      co_await schedule(std::move(coroutine));
+      co_return std::expected<expected_return_type, timeout_status>{};
+    } else {
+      co_return std::expected<expected_return_type, timeout_status>{co_await schedule(std::move(coroutine))};
+    }
   }
+
   auto result{co_await kphp::coro::when_any(std::move(coroutine), make_timeout_task(timeout))};
   if (std::holds_alternative<timeout_status>(result)) [[unlikely]] {
     co_return std::unexpected{std::move(std::get<1>(result))};
   }
-  co_return std::expected<expected_return_type, timeout_status>{std::move(std::get<0>(result))};
+
+  if constexpr (std::is_void_v<expected_return_type>) {
+    co_return std::expected<expected_return_type, timeout_status>{};
+  } else {
+    co_return std::expected<expected_return_type, timeout_status>{std::move(std::get<0>(result))};
+  }
 }
 
 template<typename rep_type, typename period_type>
diff --git a/runtime-light/utils/concepts.h b/runtime-light/metaprogramming/concepts.h
similarity index 89%
rename from runtime-light/utils/concepts.h
rename to runtime-light/metaprogramming/concepts.h
index a2db5a90fe..0912acd607 100644
--- a/runtime-light/utils/concepts.h
+++ b/runtime-light/metaprogramming/concepts.h
@@ -8,6 +8,8 @@
 #include <cstddef>
 #include <functional>
 
+namespace kphp::concepts {
+
 template<typename T>
 concept standard_layout = std::is_standard_layout_v<T>;
 
@@ -18,3 +20,5 @@ concept hashable = requires(T t) {
 
 template<typename type, typename... types>
 concept in_types = (std::same_as<type, types> || ...);
+
+} // namespace kphp::concepts
diff --git a/runtime-light/metaprogramming/type-functions.h b/runtime-light/metaprogramming/type-functions.h
new file mode 100644
index 0000000000..350fa453d7
--- /dev/null
+++ b/runtime-light/metaprogramming/type-functions.h
@@ -0,0 +1,23 @@
+//  Compiler for PHP (aka KPHP)
+//  Copyright (c) 2025 LLC «V Kontakte»
+//  Distributed under the GPL v3 License, see LICENSE.notice.txt
+
+#pragma once
+
+#include <cstddef>
+#include <type_traits>
+#include <variant>
+
+namespace kphp::type_functions {
+
+template<typename variant_type, typename T, size_t index = 0>
+requires(index < std::variant_size_v<variant_type>)
+consteval size_t variant_index() noexcept {
+  if constexpr (std::is_same_v<std::variant_alternative_t<index, variant_type>, T>) {
+    return index;
+  } else {
+    return variant_index<variant_type, T, index + 1>();
+  }
+}
+
+} // namespace kphp::type_functions
diff --git a/runtime-light/runtime-light.cmake b/runtime-light/runtime-light.cmake
index 3cc64e6e03..cbb74d4d38 100644
--- a/runtime-light/runtime-light.cmake
+++ b/runtime-light/runtime-light.cmake
@@ -22,7 +22,6 @@ include(${RUNTIME_LIGHT_DIR}/coroutine/coroutine.cmake)
 include(${RUNTIME_LIGHT_DIR}/server/server.cmake)
 include(${RUNTIME_LIGHT_DIR}/stdlib/stdlib.cmake)
 include(${RUNTIME_LIGHT_DIR}/tl/tl.cmake)
-include(${RUNTIME_LIGHT_DIR}/utils/utils.cmake)
 include(${RUNTIME_LIGHT_DIR}/state/state.cmake)
 include(${RUNTIME_LIGHT_DIR}/memory-resource-impl/memory-resource-impl.cmake)
 
diff --git a/runtime-light/utils/php-assert.cpp b/runtime-light/stdlib/diagnostics/php-assert.cpp
similarity index 100%
rename from runtime-light/utils/php-assert.cpp
rename to runtime-light/stdlib/diagnostics/php-assert.cpp
diff --git a/runtime-light/utils/null_coalesce.h b/runtime-light/stdlib/operators/null_coalesce.h
similarity index 100%
rename from runtime-light/utils/null_coalesce.h
rename to runtime-light/stdlib/operators/null_coalesce.h
diff --git a/runtime-light/stdlib/stdlib.cmake b/runtime-light/stdlib/stdlib.cmake
index a176dac8f5..22ceaece1f 100644
--- a/runtime-light/stdlib/stdlib.cmake
+++ b/runtime-light/stdlib/stdlib.cmake
@@ -8,6 +8,7 @@ prepend(
   diagnostics/backtrace.cpp
   diagnostics/contextual-logger.cpp
   diagnostics/error-handling-state.cpp
+  diagnostics/php-assert.cpp
   file/resource.cpp
   fork/fork-state.cpp
   fork/wait-queue-state.cpp
diff --git a/runtime-light/stdlib/string/regex-state.h b/runtime-light/stdlib/string/regex-state.h
index d7ebee625d..6d6fb64b1e 100644
--- a/runtime-light/stdlib/string/regex-state.h
+++ b/runtime-light/stdlib/string/regex-state.h
@@ -10,11 +10,11 @@
 #include "common/mixin/not_copyable.h"
 #include "runtime-common/core/allocator/script-allocator.h"
 #include "runtime-common/core/std/containers.h"
+#include "runtime-light/metaprogramming/concepts.h"
 #include "runtime-light/stdlib/string/regex-include.h"
-#include "runtime-light/utils/concepts.h"
 
 struct RegexInstanceState final : private vk::not_copyable {
-  template<hashable Key, typename Value>
+  template<kphp::concepts::hashable Key, typename Value>
   using unordered_map = kphp::stl::unordered_map<Key, Value, kphp::memory::script_allocator>;
 
   static constexpr size_t MAX_SUBPATTERNS_COUNT = 512;
diff --git a/runtime-light/tl/tl-core.h b/runtime-light/tl/tl-core.h
index 9c9d378d28..6be470c403 100644
--- a/runtime-light/tl/tl-core.h
+++ b/runtime-light/tl/tl-core.h
@@ -15,8 +15,8 @@
 #include "common/algorithms/find.h"
 #include "runtime-common/core/allocator/script-allocator.h"
 #include "runtime-common/core/std/containers.h"
+#include "runtime-light/metaprogramming/concepts.h"
 #include "runtime-light/stdlib/diagnostics/logs.h"
-#include "runtime-light/utils/concepts.h"
 
 namespace tl {
 
@@ -66,7 +66,7 @@ class storer {
     m_buffer.append_range(bytes);
   }
 
-  template<standard_layout T, standard_layout U>
+  template<kphp::concepts::standard_layout T, kphp::concepts::standard_layout U>
   requires std::convertible_to<U, T>
   void store_trivial(const U& t) noexcept {
     store_bytes({reinterpret_cast<const std::byte*>(std::addressof(t)), sizeof(T)});
@@ -136,7 +136,7 @@ class fetcher {
     return bytes;
   }
 
-  template<standard_layout T>
+  template<kphp::concepts::standard_layout T>
   std::optional<T> fetch_trivial() noexcept {
     if (m_remaining < sizeof(T)) {
       return std::nullopt;
diff --git a/runtime-light/utils/utils.cmake b/runtime-light/utils/utils.cmake
deleted file mode 100644
index 911086ea12..0000000000
--- a/runtime-light/utils/utils.cmake
+++ /dev/null
@@ -1 +0,0 @@
-prepend(RUNTIME_LIGHT_UTILS_SRC utils/ php-assert.cpp)