ngtcp2_conn_open_uni_stream
===========================

Synopsis
--------

*#include <ngtcp2/ngtcp2.h>*

.. function:: int ngtcp2_conn_open_uni_stream(ngtcp2_conn *conn, int64_t *pstream_id, void *stream_user_data)

    
    `ngtcp2_conn_open_uni_stream` opens new unidirectional stream.  The
    *stream_user_data* is the user data specific to the stream.  The
    stream ID of the opened stream is stored in *\*pstream_id*.
    
    Application can call this function before handshake completes.  For
    0-RTT packet, application can call this function after calling
    `ngtcp2_conn_decode_and_set_0rtt_transport_params`.  For 1-RTT
    packet, application can call this function after calling
    `ngtcp2_conn_decode_and_set_remote_transport_params` and
    `ngtcp2_conn_install_tx_key`.  If ngtcp2 crypto support library is
    used, application can call this function after calling
    `ngtcp2_crypto_derive_and_install_tx_key` for 1-RTT packet.
    
    This function returns 0 if it succeeds, or one of the following
    negative error codes:
    
    :macro:`NGTCP2_ERR_NOMEM`
        Out of memory
    :macro:`NGTCP2_ERR_STREAM_ID_BLOCKED`
        The remote endpoint does not allow *stream_id* yet.