src/Time/BrokenTime.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_BROKEN_TIME_HPP
  25 #define XCSOAR_BROKEN_TIME_HPP
  26
  27 #include "Compiler.h"
  28
  29 #include <type_traits>
  30
  31 #include <stdint.h>
  32
  33 /**
  34  * A broken-down representation of a time.
  35  */
  36 struct BrokenTime {
  37   /**
  38    * Hour of day, 0-23.
  39    */
  40   uint8_t hour;
  41
  42   /**
  43    * Minute, 0-59.
  44    */
  45   uint8_t minute;
  46
  47   /**
  48    * Second, 0-59.
  49    */
  50   uint8_t second;
  51
  52   /**
  53    * Non-initializing default constructor.
  54    */
  55   BrokenTime() = default;
  56
  57   constexpr
  58   BrokenTime(unsigned _hour, unsigned _minute, unsigned _second=0)
  59     :hour(_hour), minute(_minute), second(_second) {}
  60
  61   constexpr
  62   bool operator==(const BrokenTime other) const {
  63     return hour == other.hour && minute == other.minute &&
  64       second == other.second;
  65   }
  66
  67   constexpr
  68   bool operator>(const BrokenTime other) const {
  69     return hour > other.hour ||
  70       (hour == other.hour && (minute > other.minute ||
  71                               (minute == other.minute && second > other.second)));
  72   }
  73
  74   /**
  75    * Returns an instance that fails the Plausible() check.
  76    */
  77   constexpr
  78   static BrokenTime Invalid() {
  79     return BrokenTime(24, 60, 60);
  80   }
  81
  82   /**
  83    * Does this object contain plausible values?
  84    */
  85   constexpr
  86   bool Plausible() const {
  87     return hour < 24 && minute < 60 && second < 60;
  88   }
  89
  90   /**
  91    * Returns the number of seconds which have passed on this day.
  92    */
  93   constexpr
  94   unsigned GetSecondOfDay() const {
  95     return hour * 3600u + minute * 60u + second;
  96   }
  97
  98   /**
  99    * Construct a BrokenTime object from the specified number of
 100    * seconds which have passed on this day.
 101    *
 102    * @param second_of_day 0 .. 3600*24-1
 103    */
 104   gcc_const
 105   static BrokenTime FromSecondOfDay(unsigned second_of_day);
 106
 107   /**
 108    * A wrapper for FromSecondOfDay() which allows values bigger than
 109    * or equal to 3600*24.
 110    */
 111   gcc_const
 112   static BrokenTime FromSecondOfDayChecked(unsigned second_of_day);
 113
 114   /**
 115    * Returns a BrokenTime that has the specified number of seconds
 116    * added to it.  It properly wraps around midnight.
 117    *
 118    * @param seconds the number of seconds to add
 119    */
 120   gcc_pure
 121   BrokenTime operator+(unsigned seconds) const;
 122
 123   /**
 124    * Returns a BrokenTime that has the specified number of seconds
 125    * added to it.  It properly wraps around midnight.
 126    *
 127    * @param seconds the number of seconds to add; may be negative
 128    */
 129   gcc_pure
 130   BrokenTime operator+(int seconds) const;
 131
 132   gcc_pure
 133   BrokenTime operator-(int seconds) const {
 134     return *this + (-seconds);
 135   }
 136
 137   gcc_pure
 138   BrokenTime operator-(unsigned seconds) const {
 139     return *this - int(seconds);
 140   }
 141 };
 142
 143 static_assert(std::is_trivial<BrokenTime>::value, "type is not trivial");
 144
 145 #endif