Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Set options on the context.

boost::system::error_code set_options(
    options o,
    boost::system::error_code & ec);

This function may be used to configure the SSL options used by the context.

o: A bitmask of options. The available option values are defined in the context_base class. The options are bitwise-ored with any existing value for the options.
ec: Set to indicate what error occurred, if any.