From 217c337233454a41b41176b43577ef534dd0fe97 Mon Sep 17 00:00:00 2001
From: jzmaddock <john@johnmaddock.co.uk>
Date: Sun, 10 Jan 2016 18:10:17 +0000
Subject: [PATCH] Fix result of add_reference<const void>. Also update tests.
 See https://svn.boost.org/trac/boost/ticket/11900.

---
 include/boost/type_traits/add_reference.hpp | 6 +++---
 test/add_lvalue_reference_test.cpp          | 7 ++++++-
 test/add_reference_test.cpp                 | 5 +++++
 test/add_rvalue_reference_test.cpp          | 5 +++++
 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/include/boost/type_traits/add_reference.hpp b/include/boost/type_traits/add_reference.hpp
index 526f259..3c91415 100644
--- a/include/boost/type_traits/add_reference.hpp
+++ b/include/boost/type_traits/add_reference.hpp
@@ -49,9 +49,9 @@ template <class T> struct add_reference<T&>
 // these full specialisations are always required:
 template <> struct add_reference<void> { typedef void type; };
 #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
-template <> struct add_reference<const void> { typedef void type; };
-template <> struct add_reference<const volatile void> { typedef void type; };
-template <> struct add_reference<volatile void> { typedef void type; };
+template <> struct add_reference<const void> { typedef const void type; };
+template <> struct add_reference<const volatile void> { typedef const volatile void type; };
+template <> struct add_reference<volatile void> { typedef volatile void type; };
 #endif
 
 } // namespace boost
diff --git a/test/add_lvalue_reference_test.cpp b/test/add_lvalue_reference_test.cpp
index 1a9c1cb..0dd1af1 100644
--- a/test/add_lvalue_reference_test.cpp
+++ b/test/add_lvalue_reference_test.cpp
@@ -52,7 +52,12 @@ TT_TEST_BEGIN(add_lvalue_reference)
    add_lvalue_reference_test_13a();
 #endif
 
-TT_TEST_END
+   BOOST_CHECK_TYPE(tt::add_lvalue_reference<void>::type, void);
+   BOOST_CHECK_TYPE(tt::add_lvalue_reference<const void>::type, const void);
+   BOOST_CHECK_TYPE(tt::add_lvalue_reference<const volatile void>::type, const volatile void);
+   BOOST_CHECK_TYPE(tt::add_lvalue_reference<volatile void>::type, volatile void);
+   
+   TT_TEST_END
 
 
 
diff --git a/test/add_reference_test.cpp b/test/add_reference_test.cpp
index 458ceb5..35cf76c 100644
--- a/test/add_reference_test.cpp
+++ b/test/add_reference_test.cpp
@@ -52,6 +52,11 @@ TT_TEST_BEGIN(add_reference)
    add_reference_test_13a();
 #endif
 
+   BOOST_CHECK_TYPE(tt::add_reference<void>::type, void);
+   BOOST_CHECK_TYPE(tt::add_reference<const void>::type, const void);
+   BOOST_CHECK_TYPE(tt::add_reference<const volatile void>::type, const volatile void);
+   BOOST_CHECK_TYPE(tt::add_reference<volatile void>::type, volatile void);
+
 TT_TEST_END
 
 
diff --git a/test/add_rvalue_reference_test.cpp b/test/add_rvalue_reference_test.cpp
index 92c6cc8..caa2869 100644
--- a/test/add_rvalue_reference_test.cpp
+++ b/test/add_rvalue_reference_test.cpp
@@ -69,6 +69,11 @@ TT_TEST_BEGIN(add_rvalue_reference)
    add_rvalue_reference_test_13a();
 #endif
 
+   BOOST_CHECK_TYPE(tt::add_rvalue_reference<void>::type, void);
+   BOOST_CHECK_TYPE(tt::add_rvalue_reference<const void>::type, const void);
+   BOOST_CHECK_TYPE(tt::add_rvalue_reference<const volatile void>::type, const volatile void);
+   BOOST_CHECK_TYPE(tt::add_rvalue_reference<volatile void>::type, volatile void);
+   
 TT_TEST_END