From: Christopher Dykes <cdykes@fb.com>
Date: Fri, 7 Jul 2017 09:59:14 +0000 (-0700)
Subject: Determine noexcept'ness of folly::Optional with std::is_nothrow_constructible
X-Git-Tag: v2017.07.10.00~4
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f0dfe0f699c68867eccde9dda9fe1617ef31303e;p=folly.git

Determine noexcept'ness of folly::Optional with std::is_nothrow_constructible

Summary: Because MSVC is not happy about how it's written now.

Reviewed By: yfeldblum

Differential Revision: D5378740

fbshipit-source-id: 8b77d1a05da75b331e0cb72bd0ad859b89e54b36
---

diff --git a/folly/Optional.h b/folly/Optional.h
index c6980c18..ce8bcf1a 100644
--- a/folly/Optional.h
+++ b/folly/Optional.h
@@ -128,8 +128,8 @@ class Optional {
   }
 
   template <typename... Args>
-  explicit Optional(in_place_t, Args&&... args)
-    noexcept(noexcept(::new (nullptr) Value(std::declval<Args&&>()...))) {
+  explicit Optional(in_place_t, Args&&... args) noexcept(
+      std::is_nothrow_constructible<Value, Args...>::value) {
     construct(std::forward<Args>(args)...);
   }