Add test/result_value_construct4.cpp. Refs #104.

test/CMakeLists.txt

@@ -161,3 +161,4 @@ boost_test(TYPE run SOURCES result_value_construct3.cpp)
 boost_test(TYPE run SOURCES result_error_construct3.cpp)
 boost_test(TYPE run SOURCES result_emplace.cpp)
 boost_test(TYPE run SOURCES result_error_construct4.cpp)
+boost_test(TYPE run SOURCES result_value_construct4.cpp)

test/Jamfile.v2

@@ -191,3 +191,4 @@ run result_value_construct3.cpp : : : $(CPP11) ;
 run result_error_construct3.cpp : : : $(CPP11) ;
 run result_emplace.cpp : : : $(CPP11) ;
 run result_error_construct4.cpp : : : $(CPP11) ;
+run result_value_construct4.cpp : : : $(CPP11) ;

test/result_value_construct4.cpp

@@ -0,0 +1,62 @@
+// Copyright 2023 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/result.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+using namespace boost::system;
+
+// Tricky mixed construction cases
+// https://github.com/boostorg/system/issues/104
+// https://brevzin.github.io//c++/2023/01/18/optional-construction/
+
+int main()
+{
+    {
+        result<int> r( make_error_code( errc::invalid_argument ) );
+        result<result<int>> r2( r );
+
+        BOOST_TEST( r2.has_value() ) && BOOST_TEST_EQ( r2.value(), r );
+    }
+
+    {
+        result<int> r( 5 );
+        result<result<int>> r2( r );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), r );
+    }
+
+    {
+        result<int> const r( make_error_code( errc::invalid_argument ) );
+        result<result<int>> r2( r );
+
+        BOOST_TEST( r2.has_value() ) && BOOST_TEST_EQ( r2.value(), r );
+    }
+
+    {
+        result<int> const r( 5 );
+        result<result<int>> r2( r );
+
+        BOOST_TEST( r2.has_value() ) && BOOST_TEST_EQ( r2.value(), r );
+    }
+
+    {
+        result<int> r( make_error_code( errc::invalid_argument ) );
+        result<result<int>> r2( std::move( r ) );
+
+        BOOST_TEST( r2.has_value() ) && BOOST_TEST_EQ( r2.value(), r );
+    }
+
+    {
+        result<int> r( 5 );
+        result<result<int>> r2( std::move( r ) );
+
+        BOOST_TEST( r2.has_value() ) && BOOST_TEST_EQ( r2.value(), r );
+    }
+
+    return boost::report_errors();
+}