tz.hpp

// This file lifts out of localtime.c the main structures that we need in
// headers so that we can use them in our implementation of time zone
// handling. The main difference with the original code is the use of
// 'chrono::time_point' as the time type. Note the C++-style comments
// are non-original comments.
 
// This appears in localtime.c and applies to the whole of this file
/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson.
*/
 
/*
** Leap second handling from Bradley White.
** POSIX-style TZ environment variable handling from Guy Harris.
*/
 
 
 
#ifndef TZ_HPP
#define TZ_HPP
 
 
#include "tzfile.h"
 
struct ttinfo {             /* time type information */
  int_fast32_t  tt_utoff;   /* UT offset in seconds */
  bool      tt_isdst;   /* used to set tm_isdst */
  int       tt_desigidx;    /* abbreviation list index */
  bool      tt_ttisstd; /* transition is std time */
  bool      tt_ttisut;  /* transition is UT */
};
 
struct lsinfo {             /* leap second information */
  time_t        ls_trans;   /* transition time */
  int_fast64_t  ls_corr;    /* correction to apply */
};
 
#define SMALLEST(a, b)  (((a) < (b)) ? (a) : (b))
#define BIGGEST(a, b)   (((a) > (b)) ? (a) : (b))
 
#ifdef TZNAME_MAX
#define MY_TZNAME_MAX   TZNAME_MAX
#endif /* defined TZNAME_MAX */
#ifndef TZNAME_MAX
#define MY_TZNAME_MAX   255
#endif /* !defined TZNAME_MAX */
 
const char      gmt[] = "GMT";
 
struct state {
  int       leapcnt;
  int       timecnt;
  int       typecnt;
  int       charcnt;
  bool      goback;
  bool      goahead;
  time_t        ats[TZ_MAX_TIMES];
  unsigned char types[TZ_MAX_TIMES];
  struct ttinfo ttis[TZ_MAX_TYPES];
  char      chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
                              (2 * (MY_TZNAME_MAX + 1)))];
  struct lsinfo lsis[TZ_MAX_LEAPS];
 
  /* The time type to use for early times or if no transitions.
     It is always zero for recent tzdb releases.
     It might be nonzero for data from tzdb 2018e or earlier.  */
  int defaulttype;
};
 
 
#endif