I'm having problems with mbstate_t:

On HP-UX spe192 B.11.11 U 9000/800 (tb)

  $ cc -V -g -Isrc +z -c -o src/text.pic.o src/text.c
  cpp.ansi: HP92453-01 B.11.11.12 HP C Preprocessor (ANSI)
  ccom: HP92453-01 B.11.X.32509-32512.GP HP C Compiler
  cc: "src/text.c", line 307: error 1000: Unexpected symbol: "ps1".
  cc: "src/text.c", line 307: error 1588: "mbstate_t" undefined.
  cc: "src/text.c", line 307: error 1588: "ps2" undefined.
  cc: "src/text.c", line 309: error 1588: "ps1" undefined.
  ...

On HP-UX spe176 B.11.23 U ia64 (tb) I get:

  $ cc -V -g -Isrc +z -c -o src/text.pic.o src/text.c
  cc: HP aC++/ANSI C B3910B A.06.01 [Jan 05 2005]
  "src/text.c", line 307: error #2020: identifier "mbstate_t" is undefined
          mbstate_t ps1, ps2;
          ^
Would anyone happen to know what the problem is? How can I fix it? I don't
know these compilers, I'm just trying to make sure my code compiles ok
on HP-UX.

Thanks,
Mike