From cb4a4cdde7792b3d1345f491616d925bddc17a0f Mon Sep 17 00:00:00 2001
From: Kohei Takahashi <flast@flast.jp>
Date: Tue, 8 May 2018 00:23:04 +0900
Subject: [PATCH] It should be default constructible

---
 include/boost/fusion/support/detail/propagate_trivialness.hpp | 3 +++
 test/support/propagate_trivialness.cpp                        | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/include/boost/fusion/support/detail/propagate_trivialness.hpp b/include/boost/fusion/support/detail/propagate_trivialness.hpp
index fdb6b57a..a1c22bea 100644
--- a/include/boost/fusion/support/detail/propagate_trivialness.hpp
+++ b/include/boost/fusion/support/detail/propagate_trivialness.hpp
@@ -19,6 +19,9 @@ struct trivial_base { };
 
 struct non_trivial_base
 {
+    BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
+    BOOST_DEFAULTED_FUNCTION(non_trivial_base() BOOST_NOEXCEPT, {})
+
     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
     non_trivial_base(non_trivial_base const&) BOOST_NOEXCEPT { }
 };
diff --git a/test/support/propagate_trivialness.cpp b/test/support/propagate_trivialness.cpp
index e4d90af2..17050ca4 100644
--- a/test/support/propagate_trivialness.cpp
+++ b/test/support/propagate_trivialness.cpp
@@ -11,12 +11,16 @@
 #include <boost/mpl/assert.hpp>
 #include <boost/type_traits/is_convertible.hpp>
 #include <boost/type_traits/is_base_of.hpp>
+#include <boost/type_traits/is_default_constructible.hpp>
 #include "trivial.hpp"
 
 using namespace boost;
 using namespace boost::fusion::detail;
 
 
+BOOST_MPL_ASSERT((is_default_constructible<trivial_base>));
+BOOST_MPL_ASSERT((is_default_constructible<non_trivial_base>));
+
 BOOST_FUSION_ASSERT_FALLBACK((is_trivially_copyable<trivial_base>));
 BOOST_MPL_ASSERT_NOT((is_trivially_copyable<non_trivial_base>));