### prepend

Completion token type used to specify that the completion handler arguments should be passed additional values before the results of the operation.

    template<
        typename CompletionToken,
        typename... Values>
    constexpr prepend_t< decay_t< CompletionToken >, decay_t< Values >... > prepend(
        CompletionToken && completion_token,
        Values &&... values);

##### Requirements

Header: `asio/prepend.hpp`

Convenience header: `asio.hpp`