id summary reporter owner description type status milestone component version severity resolution keywords cc 10567 is not inside rivercheng@… chris_kohlhoff According to the document, include should implicitly include , but actually it is missing in asio.hpp and has to be included explicitly. I am not sure whether this is intended or not. If it is intended, then the document needs to be updated. Bugs new To Be Determined asio Boost 1.56.0 Regression