diff --git a/include/boost/system/result.hpp b/include/boost/system/result.hpp
index 46782dd..52c649a 100644
--- a/include/boost/system/result.hpp
+++ b/include/boost/system/result.hpp
@@ -1,5 +1,5 @@
-#ifndef BOOST_RESULT_RESULT_HPP_INCLUDED
-#define BOOST_RESULT_RESULT_HPP_INCLUDED
+#ifndef BOOST_SYSTEM_RESULT_HPP_INCLUDED
+#define BOOST_SYSTEM_RESULT_HPP_INCLUDED
 
 // Copyright 2017, 2021 Peter Dimov.
 // Distributed under the Boost Software License, Version 1.0.
@@ -18,16 +18,20 @@
 
 namespace boost
 {
-namespace result
+namespace system
 {
 
+class error_code;
+
 // throw_exception_from_error_code
 
-BOOST_NORETURN void throw_exception_from_error_code( std::error_code const & e )
+BOOST_NORETURN inline void throw_exception_from_error_code( std::error_code const & e )
 {
     boost::throw_exception( std::system_error( e ) );
 }
 
+BOOST_NORETURN inline void throw_exception_from_error_code( error_code const & e );
+
 // in_place_*
 
 using in_place_value_t = variant2::in_place_index_t<0>;
@@ -38,7 +42,7 @@ constexpr in_place_error_t in_place_error{};
 
 // result
 
-template<class T, class E = std::error_code> class result
+template<class T, class E = error_code> class result
 {
 private:
 
@@ -335,7 +339,7 @@ template<class Ch, class Tr, class T, class E> std::basic_ostream<Ch, Tr>& opera
     return os;
 }
 
-} // namespace result
+} // namespace system
 } // namespace boost
 
-#endif // #ifndef BOOST_RESULT_RESULT_HPP_INCLUDED
+#endif // #ifndef BOOST_SYSTEM_RESULT_HPP_INCLUDED
diff --git a/test/result_copy_assign.cpp b/test/result_copy_assign.cpp
index 3f11082..515cbc0 100644
--- a/test/result_copy_assign.cpp
+++ b/test/result_copy_assign.cpp
@@ -2,14 +2,14 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 #include <system_error>
 #include <iosfwd>
 #include <cerrno>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_copy_construct.cpp b/test/result_copy_construct.cpp
index bd9a5b6..2ce15bd 100644
--- a/test/result_copy_construct.cpp
+++ b/test/result_copy_construct.cpp
@@ -2,11 +2,11 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_default_construct.cpp b/test/result_default_construct.cpp
index 134e526..b054d50 100644
--- a/test/result_default_construct.cpp
+++ b/test/result_default_construct.cpp
@@ -2,11 +2,11 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_eq.cpp b/test/result_eq.cpp
index d0c1ac6..b9f9da9 100644
--- a/test/result_eq.cpp
+++ b/test/result_eq.cpp
@@ -2,13 +2,13 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <system_error>
 #include <iosfwd>
 #include <cerrno>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_error_access.cpp b/test/result_error_access.cpp
index b035dd6..c103f8a 100644
--- a/test/result_error_access.cpp
+++ b/test/result_error_access.cpp
@@ -2,12 +2,12 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 #include <string>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_error_construct.cpp b/test/result_error_construct.cpp
index c96b9f8..bb96816 100644
--- a/test/result_error_construct.cpp
+++ b/test/result_error_construct.cpp
@@ -2,14 +2,14 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 #include <system_error>
 #include <string>
 #include <cerrno>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_move_assign.cpp b/test/result_move_assign.cpp
index 43ac62f..d29c0ae 100644
--- a/test/result_move_assign.cpp
+++ b/test/result_move_assign.cpp
@@ -2,14 +2,14 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 #include <system_error>
 #include <iosfwd>
 #include <cerrno>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_move_construct.cpp b/test/result_move_construct.cpp
index 08459e5..7209019 100644
--- a/test/result_move_construct.cpp
+++ b/test/result_move_construct.cpp
@@ -2,11 +2,11 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_swap.cpp b/test/result_swap.cpp
index 539f7d6..c485e02 100644
--- a/test/result_swap.cpp
+++ b/test/result_swap.cpp
@@ -2,13 +2,13 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <system_error>
 #include <iosfwd>
 #include <cerrno>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_value_access.cpp b/test/result_value_access.cpp
index d3e1abe..95eb248 100644
--- a/test/result_value_access.cpp
+++ b/test/result_value_access.cpp
@@ -2,11 +2,11 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {
diff --git a/test/result_value_construct.cpp b/test/result_value_construct.cpp
index 7e61934..a44cd8d 100644
--- a/test/result_value_construct.cpp
+++ b/test/result_value_construct.cpp
@@ -2,11 +2,11 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
-#include <boost/result/result.hpp>
+#include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
 
-using namespace boost::result;
+using namespace boost::system;
 
 struct X
 {