Compatible with windows vs2017 (#71)

Co-authored-by: MarsZhang <6671605@è[email protected]>

Author: makefriend8

.bazelrc

@@ -1,3 +1,5 @@
-build --cxxopt=-std=c++17
+build --enable_platform_specific_config
+build:linux --cxxopt=-std=c++17
+build:windows --cxxopt=-std:c++17
 
 try-import %workspace%/user.bazelrc

source/utils/circular_buffer.h

@@ -16,6 +16,7 @@
 
 #include <deque>
 #include <mutex>
+#include <optional>
 
 namespace cpp2sky {