[Bug c++/116931] False "duplicate 'const'" errors when typedefs used on pointer types in function definitions

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116931

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
[dcl.type.general] p2:

  As a general rule, at most one defining-type-specifier is allowed in the
complete
  decl-specifier-seq of a declaration or in a defining-type-specifier-seq, and
at most
  one type-specifier is allowed in a type-specifier-seq. The only exceptions to
this
  rule are the following:
   — const can be combined with any type specifier except itself.
   — [...]

So you can't have const const T or const T const.

const T* const is of course not the same as const const T* and so is OK.