When supported by a compiler, Asio can use variadic templates to implement the basic_socket_streambuf::connect() and basic_socket_iostream::connect() functions.

Support for variadic templates is automatically enabled for g++ 4.3 and later, when the -std=c++0x or -std=gnu++0x compiler options are used. It may be disabled by defining ASIO_DISABLE_VARIADIC_TEMPLATES, or explicitly enabled for other compilers by defining ASIO_HAS_VARIADIC_TEMPLATES.