Boost C++ Libraries

boost/date_time/gregorian/greg_month.hpp

#ifndef GREG_MONTH_HPP___
#define GREG_MONTH_HPP___

/* Copyright (c) 2002,2003, 2020 CrystalClear Software, Inc.
 * Use, modification and distribution is subject to the 
 * Boost Software License, Version 1.0. (See accompanying
 * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
 * Author: Jeff Garland, Bart Garst
 * $Date$
 */

#include <boost/date_time/constrained_value.hpp>
#include <boost/date_time/date_defs.hpp>
#include <boost/date_time/compiler_config.hpp>
#include <stdexcept>
#include <string>

namespace boost {
namespace gregorian {

  typedef date_time::months_of_year months_of_year;

  //bring enum values into the namespace
  using date_time::Jan;
  using date_time::Feb;
  using date_time::Mar;
  using date_time::Apr;
  using date_time::May;
  using date_time::Jun;
  using date_time::Jul;
  using date_time::Aug;
  using date_time::Sep;
  using date_time::Oct;
  using date_time::Nov;
  using date_time::Dec;
  using date_time::NotAMonth;
  using date_time::NumMonths;

  //! Exception thrown if a greg_month is constructed with a value out of range
  struct BOOST_SYMBOL_VISIBLE bad_month : public std::out_of_range
  {
    bad_month() : std::out_of_range(std::string("Month number is out of range 1..12")) {}
  };
  //! Build a policy class for the greg_month_rep
  typedef CV::simple_exception_policy<unsigned short, 1, 12, bad_month> greg_month_policies;
  //! A constrained range that implements the gregorian_month rules
  typedef CV::constrained_value<greg_month_policies> greg_month_rep;


  //! Wrapper class to represent months in gregorian based calendar
  class BOOST_SYMBOL_VISIBLE greg_month : public greg_month_rep {
  public:
    typedef date_time::months_of_year month_enum;

    //! Construct a month from the months_of_year enumeration
    BOOST_CXX14_CONSTEXPR greg_month(month_enum theMonth) :
      greg_month_rep(static_cast<greg_month_rep::value_type>(theMonth)) {}
    //! Construct from a short value
    BOOST_CXX14_CONSTEXPR greg_month(value_type theMonth) : greg_month_rep(theMonth) {}
    //! Convert the value back to a short
    BOOST_CXX14_CONSTEXPR operator value_type()  const {return value_;}
    //! Returns month as number from 1 to 12
    BOOST_CXX14_CONSTEXPR value_type as_number() const {return value_;}
    BOOST_CXX14_CONSTEXPR month_enum as_enum() const {return static_cast<month_enum>(value_);}

    //! Returns 3 char english string for the month ex: Jan, Feb, Mar, Apr
    const char*
    as_short_string() const
    {
      static const char* const short_month_names[NumMonths]
        = {"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec", "NAM"};
      return short_month_names[value_-1];
    }

    //! Returns full name of month as string in english ex: January, February
    const char*
    as_long_string() const
    {
      static const char* const long_month_names[NumMonths]
        = {"January","February","March","April","May","June","July","August",
           "September","October","November","December","NotAMonth"};
      return long_month_names[value_-1];
    }

#ifndef BOOST_NO_STD_WSTRING

    //! Returns 3 wchar_t english string for the month ex: Jan, Feb, Mar, Apr
    const wchar_t*
    as_short_wstring() const
    {
      static const wchar_t* const w_short_month_names[NumMonths]
        = {L"Jan",L"Feb",L"Mar",L"Apr",L"May",L"Jun",L"Jul",L"Aug",L"Sep",L"Oct",
           L"Nov",L"Dec",L"NAM"};
      return w_short_month_names[value_-1];
    }

    //! Returns full name of month as wchar_t string in english ex: January, February
    const wchar_t*
    as_long_wstring() const
    {
      static const wchar_t* const w_long_month_names[NumMonths]
        = {L"January",L"February",L"March",L"April",L"May",L"June",L"July",L"August",
           L"September",L"October",L"November",L"December",L"NotAMonth"};
      return w_long_month_names[value_-1];
    }

#endif // BOOST_NO_STD_WSTRING

    /* parameterized as_*_string functions are intended to be called
     * from a template function: "... as_short_string(charT c='\0');" */
    const char* as_short_string(char) const
    {
      return as_short_string();
    }
    const char* as_long_string(char) const
    {
      return as_long_string();
    }
#ifndef BOOST_NO_STD_WSTRING
    const wchar_t* as_short_string(wchar_t) const
    {
      return as_short_wstring();
    }
    const wchar_t* as_long_string(wchar_t) const
    {
      return as_long_wstring();
    }
#endif // BOOST_NO_STD_WSTRING
  };

} } //namespace gregorian

#endif