From: Yedidya Feldblum <yfeldblum@fb.com>
Date: Mon, 30 Oct 2017 21:52:50 +0000 (-0700)
Subject: Simplify type_t
X-Git-Tag: v2017.11.06.00~34
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=folly.git;a=commitdiff_plain;h=ffe039c4511c9771974ead5b25762b57955ff1da

Simplify type_t

Summary:
[Folly] Simplify `type_t` by lifting the type to be aliased into the structure template parameter list.

May also fix curious build failures in some compilers.

Reviewed By: akrieger

Differential Revision: D6188953

fbshipit-source-id: 96e1c3af9c11959c0899c092933158922efa7e60
---

diff --git a/folly/Traits.h b/folly/Traits.h
index f513462a..fb797f37 100644
--- a/folly/Traits.h
+++ b/folly/Traits.h
@@ -220,15 +220,14 @@ using _t = typename T::type;
  */
 
 namespace traits_detail {
-template <class...>
+template <class T, class...>
 struct type_t_ {
-  template <class T>
-  using apply = T;
+  using type = T;
 };
 } // namespace traits_detail
 
 template <class T, class... Ts>
-using type_t = typename traits_detail::type_t_<Ts...>::template apply<T>;
+using type_t = typename traits_detail::type_t_<T, Ts...>::type;
 template <class... Ts>
 using void_t = type_t<void, Ts...>;