Add nullstream

test/Jamfile

@@ -17,3 +17,4 @@ run quoted_fill_test.cpp ;
 run ostream_joiner_test.cpp ;
 run make_ostream_joiner_test.cpp ;
 run ostream_put_test.cpp ;
+run nullstream_test.cpp ;

test/nullstream_test.cpp

@@ -0,0 +1,28 @@
+/*
+Copyright 2021 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/io/nullstream.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    {
+        boost::io::onullstream s;
+        s << "abc";
+        s << 100;
+        s << std::endl;
+        BOOST_TEST(s);
+    }
+    {
+        boost::io::wonullstream s;
+        s << L"abc";
+        s << 100;
+        s << std::endl;
+        BOOST_TEST(s);
+    }
+    return boost::report_errors();
+}