From cd4e44f3dc66a24c49ac4dc7d176cff98bcca821 Mon Sep 17 00:00:00 2001
From: Matt <citrusmoose@users.noreply.github.com>
Date: Thu, 13 Apr 2017 09:13:26 -0400
Subject: [PATCH] r #12967 make none_t constructor constexpr

---
 include/boost/none_t.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/boost/none_t.hpp b/include/boost/none_t.hpp
index 008f369..9ed9409 100644
--- a/include/boost/none_t.hpp
+++ b/include/boost/none_t.hpp
@@ -29,7 +29,7 @@ class none_t {};
 struct none_t
 {
   struct init_tag{};
-  explicit none_t(init_tag){} // to disable default constructor
+  explicit constexpr none_t(init_tag){} // to disable default constructor
 };
 
 #endif // old implementation workarounds