@subheading pr29_strerror
@anchor{pr29_strerror}
@deftypefun {const char *} {pr29_strerror} (Pr29_rc @var{rc})
@var{rc}: an @code{Pr29_rc} return code.

Convert a return code integer to a text string.  This string can be
used to output a diagnostic message to the user.

@strong{PR29_SUCCESS:} Successful operation.  This value is guaranteed to
always be zero, the remaining ones are only guaranteed to hold
non-zero values, for logical comparison purposes.

@strong{PR29_PROBLEM:} A problem sequence was encountered.

@strong{PR29_STRINGPREP_ERROR:} The character set conversion failed (only
for @code{pr29_8()} and @code{pr29_8z()}).

@strong{Return value:} Returns a pointer to a statically allocated string
containing a description of the error with the return code @code{rc}.
@end deftypefun

