Sync from upstream.

test/result_and_eq_fn1v.cpp

@@ -59,6 +59,13 @@ int& h( int& )
     return x;
 }
 
+static int fv_called;
+
+void fv()
+{
+    ++fv_called;
+}
+
 int main()
 {
     {
@@ -110,5 +117,25 @@ int main()
         BOOST_TEST( r.has_error() );
     }
 
+    {
+        result<void> r;
+        fv_called = 0;
+
+        r &= fv;
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( fv_called, 1 );
+    }
+
+    {
+        result<void, E> r( in_place_error );
+        fv_called = 0;
+
+        r &= fv;
+
+        BOOST_TEST( r.has_error() );
+        BOOST_TEST_EQ( fv_called, 0 );
+    }
+
     return boost::report_errors();
 }

test/result_and_fn1v.cpp

@@ -55,6 +55,20 @@ int k()
     return 7;
 }
 
+static int fv1_called_with;
+
+void fv1( int x )
+{
+    fv1_called_with = x;
+}
+
+static int fv2_called;
+
+void fv2()
+{
+    ++fv2_called;
+}
+
 int main()
 {
     {
@@ -199,5 +213,119 @@ int main()
         BOOST_TEST( r2.has_error() );
     }
 
+    {
+        fv1_called_with = 0;
+
+        result<int> r( 1 );
+        result<void> r2 = r & fv1;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv1_called_with, 1 );
+    }
+
+    {
+        result<int> const r( 1 );
+        result<void> r2 = r & fv1;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv1_called_with, 1 );
+    }
+
+    {
+        fv1_called_with = 0;
+
+        result<void> r2 = result<int>( 1 ) & fv1;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv1_called_with, 1 );
+    }
+
+    {
+        fv1_called_with = 0;
+
+        result<int, E> r( in_place_error );
+        result<void, E> r2 = r & fv1;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv1_called_with, 0 );
+    }
+
+    {
+        fv1_called_with = 0;
+
+        result<int, E> const r( in_place_error );
+        result<void, E> r2 = r & fv1;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv1_called_with, 0 );
+    }
+
+    {
+        fv1_called_with = 0;
+
+        result<void, E> r2 = result<int, E>( in_place_error ) & fv1;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv1_called_with, 0 );
+    }
+
+    {
+        result<void> r;
+        fv2_called = 0;
+
+        result<void> r2 = r & fv2;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv2_called, 1 );
+    }
+
+    {
+        result<void> const r;
+        fv2_called = 0;
+
+        result<void> r2 = r & fv2;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv2_called, 1 );
+    }
+
+    {
+        fv2_called = 0;
+
+        result<void> r2 = result<void>() & fv2;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv2_called, 1 );
+    }
+
+    {
+        result<void, E> r( in_place_error );
+        fv2_called = 0;
+
+        result<void, E> r2 = r & fv2;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv2_called, 0 );
+    }
+
+    {
+        result<void, E> const r( in_place_error );
+        fv2_called = 0;
+
+        result<void, E> r2 = r & fv2;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv2_called, 0 );
+    }
+
+    {
+        fv2_called = 0;
+
+        result<void, E> r2 = result<void, E>( in_place_error ) & fv2;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv2_called, 0 );
+    }
+
     return boost::report_errors();
 }