Future: some fixes re: handling of universal references

[folly.git] / folly / futures / detail / Core.h

diff --git a/folly/futures/detail/Core.h b/folly/futures/detail/Core.h
index 3124cda343b5046d0b8c8faed54de80d8c8d3edc..b196b6649ee54b02233019af16cae891477ff55b 100644 (file)
--- a/folly/futures/detail/Core.h
+++ b/folly/futures/detail/Core.h
@@ -470,9 +470,11 @@ template <template <typename ...> class T, typename... Ts,
           typename THead, typename... TTail>
 void collectVariadicHelper(const std::shared_ptr<T<Ts...>>& ctx,
                            THead&& head, TTail&&... tail) {
-  head.setCallback_([ctx](Try<typename THead::value_type>&& t) {
-    ctx->template setPartialResult<typename THead::value_type,
-                                   sizeof...(Ts) - sizeof...(TTail) - 1>(t);
+  using ValueType = typename std::decay<THead>::type::value_type;
+  std::forward<THead>(head).setCallback_([ctx](Try<ValueType>&& t) {
+    ctx->template setPartialResult<
+        ValueType,
+        sizeof...(Ts) - sizeof...(TTail)-1>(t);
   });
   // template tail-recursion
   collectVariadicHelper(ctx, std::forward<TTail>(tail)...);