  Next generation wireless networks require more stringent performance levels.
  New technologies such as Reconfigurable intelligent surfaces (RISs) and
rate-splitting multiple access (RSMA) are candidates for meeting some of the
performance requirements, including higher user rates at reduced costs.
  RSMA provides a new way of mixing the messages of multiple users, and the RIS
provides a controllable wireless environment.
  This paper provides a comprehensive survey on the various aspects of the
synergy between reconfigurable intelligent surfaces (RISs) and rate splitting
multiple access (RSMA) for next-generation (xG) wireless communications
systems.
  In particular, the paper studies more than 60 articles considering over 20
different system models where the RIS-aided RSMA system shows performance
advantage (in terms of sum-rate or outage probability) over traditional RSMA
models.
  These models include reflective RIS, simultaneously transmitting and
reflecting surfaces (STAR-RIS), as well as transmissive surfaces.
  The state-of-the-art resource management methods for RIS-assisted RSMA
communications employ traditional optimization techniques and/or machine
learning techniques.
  We outline major research challenges and multiple future research directions.
