#### basic_yield_context::caller_type

The coroutine caller type, used by the implementation.

    typedef implementation_defined caller_type;

When using Boost.Coroutine v1, this type is:

    typename coroutine<void()>::caller_type

When using Boost.Coroutine v2 (unidirectional coroutines), this type is:

    pull_coroutine<void>

###### Requirements

Header: `asio/spawn.hpp`

Convenience header: None