base-clause: : base-specifier-list
base-specifier-list: base-specifier ...opt base-specifier-list , base-specifier ...opt
base-specifier: attribute-specifier-seqopt class-or-decltype attribute-specifier-seqopt virtual access-specifieropt class-or-decltype attribute-specifier-seqopt access-specifier virtualopt class-or-decltype
class-or-decltype: nested-name-specifieropt class-name nested-name-specifier template simple-template-id decltype-specifier
access-specifier: private protected public