From 2eaba7d6d1c359556308d8805e27495509e2854a Mon Sep 17 00:00:00 2001
From: Glen Fernandes <glen.fernandes@gmail.com>
Date: Sun, 26 Aug 2018 02:08:51 -0400
Subject: [PATCH] Make empty_value<T> trivial if T is trivial

---
 include/boost/core/empty_value.hpp | 16 ++++++++++++++--
 test/empty_value_test.cpp          |  2 +-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/boost/core/empty_value.hpp b/include/boost/core/empty_value.hpp
index 8853588..b67d42c 100644
--- a/include/boost/core/empty_value.hpp
+++ b/include/boost/core/empty_value.hpp
@@ -43,7 +43,13 @@ struct empty_init_t { };
 template<class T, unsigned = 0, bool = use_empty_value_base<T>::value>
 class empty_value {
 public:
-    empty_value()
+#if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS)
+    empty_value() = default;
+#else
+    empty_value() { }
+#endif
+
+    empty_value(empty_init_t)
         : value_() { }
 
 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
@@ -79,7 +85,13 @@ template<class T, unsigned N>
 class empty_value<T, N, true>
     : T {
 public:
-    empty_value()
+#if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS)
+    empty_value() = default;
+#else
+    empty_value() { }
+#endif
+
+    empty_value(empty_init_t)
         : T() { }
 
 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
diff --git a/test/empty_value_test.cpp b/test/empty_value_test.cpp
index d7261b6..7c90594 100644
--- a/test/empty_value_test.cpp
+++ b/test/empty_value_test.cpp
@@ -34,7 +34,7 @@ void test_bool()
 {
     const boost::empty_value<bool> v1(boost::empty_init_t(), true);
     BOOST_TEST(v1.get());
-    boost::empty_value<bool> v2;
+    boost::empty_value<bool> v2 = boost::empty_init_t();
     BOOST_TEST(!v2.get());
     v2 = v1;
     BOOST_TEST(v2.get());