fix _nana_std_optional

2018-06-07 03:36:30 +08:00
parent 0290e49fbe
commit 549b3d4353
1 changed files with 1 additions and 1 deletions
--- a/include/nana/optional.hpp
+++ b/include/nana/optional.hpp
@@ -17,7 +17,7 @@

 #include <nana/c++defines.hpp>

-#ifdef _nana_std_optional
+#ifndef _nana_std_optional
 #include <optional>
 #else
 #include <stdexcept>