boostorg/asio — pull request #1 by arvidn (2013-12-17 23:14:18+00:00)
Title: support dynamic linking on other plaftorms than windows

the BOOST_ASIO_EXPORT macro is necessary to export a class (because in header-only mode "inline" would be inserted in a place it can't be). Leveraging boost.config for the export macro makes this support lots of other compilers. io_service::service needs to be exported on mac (and I believe linux) in order to have its typeinfo object be exported.