[boost] Fwd: Using 'detail' folder from a another Boost library

Hi everyone, I am trying to unify the way Boost.Beast and Boost.Asio pick an implementation of string_view (std::experimental::string_view, std::string_view). In order to do so, I am including the header file within (see PR: https://github.com/boostorg/ beast/pull/910/files). Is that a bad practice to include the a "detail" folder from another library? If so, what would you recommend to solve my unification problem? Sincerely, Jean