From 663198ae924d6bd72fca78eae2a1c25a6f51157b Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Mon, 23 May 2022 02:29:23 +0300
Subject: [PATCH] Add BOOST_NULLPTR helper macro

---
 doc/macro_reference.qbk                | 4 ++++
 include/boost/config/detail/suffix.hpp | 6 ++++++
 test/helper_macro_test.cpp             | 6 ++++++
 3 files changed, 16 insertions(+)

diff --git a/doc/macro_reference.qbk b/doc/macro_reference.qbk
index ccb44ac9..b21bf08a 100644
--- a/doc/macro_reference.qbk
+++ b/doc/macro_reference.qbk
@@ -966,6 +966,10 @@ and must be defined for all translation units in the program, including Boost li
 This macro will no longer have any effect once an official Microsoft
 release supports the CTP features.
 ]]
+[[`BOOST_NULLPTR`][
+If `BOOST_NO_CXX11_NULLPTR` is not defined (i.e. C++11 compliant compilers), expands to `nullptr`,
+otherwise expands to `0`.
+]]
 ]
 
 [endsect]
diff --git a/include/boost/config/detail/suffix.hpp b/include/boost/config/detail/suffix.hpp
index 2423c35d..cee5a965 100644
--- a/include/boost/config/detail/suffix.hpp
+++ b/include/boost/config/detail/suffix.hpp
@@ -1069,6 +1069,12 @@ namespace std{ using ::type_info; }
 
 #define BOOST_STATIC_CONSTEXPR  static BOOST_CONSTEXPR_OR_CONST
 
+#if !defined(BOOST_NO_CXX11_NULLPTR)
+# define BOOST_NULLPTR nullptr
+#else
+# define BOOST_NULLPTR 0
+#endif
+
 //
 // Set BOOST_HAS_STATIC_ASSERT when BOOST_NO_CXX11_STATIC_ASSERT is not defined
 //
diff --git a/test/helper_macro_test.cpp b/test/helper_macro_test.cpp
index 79549ca3..b90b3ef4 100644
--- a/test/helper_macro_test.cpp
+++ b/test/helper_macro_test.cpp
@@ -62,6 +62,10 @@ struct trait
    enum { value = b };
 };
 
+void* test_nullptr()
+{
+   return BOOST_NULLPTR;
+}
 
 int main()
 {
@@ -82,6 +86,8 @@ int main()
       {
          result += 2;
       }
+
+      test_nullptr();
    }
    catch(int)
    {