diff --git a/build/Jamfile.v2 b/build/Jamfile.v2
index 33964a308..2ad5754d3 100644
--- a/build/Jamfile.v2
+++ b/build/Jamfile.v2
@@ -107,6 +107,7 @@ WSOURCES =
     xml_woarchive
     polymorphic_xml_wiarchive
     polymorphic_xml_woarchive
+    codecvt_null
 ;
 
 lib boost_serialization 
diff --git a/include/boost/archive/iterators/escape.hpp b/include/boost/archive/iterators/escape.hpp
index b40914410..832720c69 100644
--- a/include/boost/archive/iterators/escape.hpp
+++ b/include/boost/archive/iterators/escape.hpp
@@ -82,7 +82,7 @@ class escape :
     }
 
    void increment(){
-        if(m_bnext != NULL && ++m_bnext < m_bend){
+        if(m_bnext != m_bend && ++m_bnext < m_bend){
             m_current_value = *m_bnext;
             return;
         }
diff --git a/include/boost/serialization/extended_type_info_no_rtti.hpp b/include/boost/serialization/extended_type_info_no_rtti.hpp
index 68df0eef5..9e56974a1 100644
--- a/include/boost/serialization/extended_type_info_no_rtti.hpp
+++ b/include/boost/serialization/extended_type_info_no_rtti.hpp
@@ -130,7 +130,6 @@ class extended_type_info_no_rtti :
     void * construct(unsigned int count, ...) const BOOST_OVERRIDE {
         // count up the arguments
         std::va_list ap;
-        va_start(ap, count);
         switch(count){
         case 0:
             return factory<typename boost::remove_const< T >::type, 0>(ap);
diff --git a/include/boost/serialization/extended_type_info_typeid.hpp b/include/boost/serialization/extended_type_info_typeid.hpp
index 656950a69..65285644c 100644
--- a/include/boost/serialization/extended_type_info_typeid.hpp
+++ b/include/boost/serialization/extended_type_info_typeid.hpp
@@ -113,7 +113,6 @@ class extended_type_info_typeid :
     void * construct(unsigned int count, ...) const BOOST_OVERRIDE {
         // count up the arguments
         std::va_list ap;
-        va_start(ap, count);
         switch(count){
         case 0:
             return factory<typename boost::remove_const< T >::type, 0>(ap);
diff --git a/include/boost/serialization/std_variant.hpp b/include/boost/serialization/std_variant.hpp
index cd927072e..c02309b48 100644
--- a/include/boost/serialization/std_variant.hpp
+++ b/include/boost/serialization/std_variant.hpp
@@ -176,7 +176,7 @@ inline void serialize(
 
 // Specialization for std::monostate
 template<class Archive>
-void serialize(Archive &ar, std::monostate &, const unsigned int /*version*/)
+void serialize(Archive &, std::monostate &, const unsigned int /*version*/)
 {}
 
 } // namespace serialization
diff --git a/include/boost/serialization/variant2.hpp b/include/boost/serialization/variant2.hpp
index da899ffc8..32deffd6a 100644
--- a/include/boost/serialization/variant2.hpp
+++ b/include/boost/serialization/variant2.hpp
@@ -7,7 +7,7 @@
 #endif
 
 /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
-// variant.hpp - non-intrusive serialization of variant types
+// variant2.hpp - non-intrusive serialization of variant types
 //
 // copyright (c) 2019 Samuel Debionne, ESRF
 //
@@ -22,8 +22,6 @@
 
 #include <boost/serialization/throw_exception.hpp>
 
-#include <variant>
-
 #include <boost/archive/archive_exception.hpp>
 
 #include <boost/mp11/list.hpp>
diff --git a/test/test_p_helper.cpp b/test/test_p_helper.cpp
index a4404e89a..e6a385e9e 100644
--- a/test/test_p_helper.cpp
+++ b/test/test_p_helper.cpp
@@ -33,7 +33,6 @@ namespace std{
 #include <vector>
 
 #include "test_tools.hpp"
-#include <boost/lexical_cast.hpp>
 #include <boost/serialization/split_free.hpp>
 #include <boost/serialization/vector.hpp>
 #include <boost/serialization/nvp.hpp>
@@ -121,7 +120,9 @@ int test_main(int /* argc */, char * /* argv */ [])
 
     std::vector<my_string> v1;
     for(int i=0; i<1000; ++i){
-        v1.push_back(my_string(boost::lexical_cast<std::string>(i % 100)));
+        char sbuffer[10];
+        std::snprintf(sbuffer, sizeof(sbuffer), "%i", i % 100);
+        v1.push_back(my_string(sbuffer));
     }
 
     // test using using polymorphic implementation.
diff --git a/test/test_variant.cpp b/test/test_variant.cpp
index 17234545b..3de1afd33 100644
--- a/test/test_variant.cpp
+++ b/test/test_variant.cpp
@@ -160,40 +160,58 @@ void test(Variant & v)
 
 #include <boost/serialization/variant.hpp>
 
-int test_main( int /* argc */, char* /* argv */[] ){
+#include <boost/variant/variant.hpp>
 
-    // boost::variant - compatible with C++03
-    {
-        boost::variant<bool, int, float, double, A, std::string> v;
-        test(v);
-        const A a;
-        boost::variant<bool, int, float, double, const A *, std::string> v1 = & a;
-        test_type(v1);
-    }
+#include <cstdio>
+
+int test_boost_variant(){
+    std::cerr << "Testing boost_variant\n";
+    boost::variant<bool, int, float, double, A, std::string> v;
+    test(v);
+    const A a;
+    boost::variant<bool, int, float, double, const A *, std::string> v1 = & a;
+    test_type(v1);
+    return EXIT_SUCCESS;
+}
+
+// boost::variant2/variant requires C++ 11
+#if BOOST_CXX_VERSION >= 201103L
+#include <boost/variant2/variant.hpp>
+
+int test_boost_variant2(){
+    std::cerr << "Testing boost_variant2\n";
+    boost::variant2::variant<bool, int, float, double, A, std::string> v;
+    test(v);
+    const A a;
+    boost::variant2::variant<bool, int, float, double, const A *, std::string> v1 = & a;
+    test_type(v1);
+    return EXIT_SUCCESS;
+}
+#endif
+
+// std::variant reqires C++ 17 or more
+#ifndef BOOST_NO_CXX17_HDR_VARIANT
+#include <variant>
+int test_std_variant(){
+    std::cerr << "Testing Std Variant\n";
+    std::variant<bool, int, float, double, A, std::string> v;
+    test(v);
+    const A a;
+    std::variant<bool, int, float, double, const A *, std::string> v1 = & a;
+    test_type(v1);
+    return EXIT_SUCCESS;
+}
+#endif
 
-    // boost::variant2/variant requires C++ 11
+int test_main( int /* argc */, char* /* argv */[] ){
+    return test_boost_variant()
     #if BOOST_CXX_VERSION >= 201103L
-    {
-        boost::variant2::variant<bool, int, float, double, A, std::string> v;
-        test(v);
-        const A a;
-        boost::variant2::variant<bool, int, float, double, const A *, std::string> v1 = & a;
-        test_type(v1);
-    }
+    || test_boost_variant2()
     #endif
-
-    // std::variant reqires C++ 17 or more
     #ifndef BOOST_NO_CXX17_HDR_VARIANT
-    {
-        std::variant<bool, int, float, double, A, std::string> v;
-        test(v);
-        const A a;
-        std::variant<bool, int, float, double, const A *, std::string> v1 = & a;
-        test_type(v1);
-    }
+    || test_std_variant()
     #endif
-
-    return EXIT_SUCCESS;
+    ;
 }
 
 // EOF