c-opt-type-suffix-key is a variable defined in `cc-engine.el'.
Its value is

  • Automatically becomes buffer-local when set.

Regexp matching operators that might follow after a type, or nil in
languages that don't have such operators. The end of the first
submatch is taken as the end of the operator. This should not match
things like C++ template arglists if `c-recognize-<>-arglists' is set.
It's undefined whether identifier syntax (see `c-identifier-syntax-table')
is in effect or not.