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std::time_put::put, std::time_put::do_put

From cppreference.com
< cpp‎ | locale‎ | time put
Defined in header <locale>
public:

iter_type put( iter_type out, std::ios_base& str,
               char_type fill, const std::tm* t,

               const charT* fmtbeg, const charT* fmtend ) const;
(1)
public:

iter_type put( iter_type out, std::ios_base& str,
               char_type fill, const std::tm* t,

               char format, char modifier = 0 ) const;
(1)
protected:

virtual iter_type do_put( iter_type out, std::ios_base& str,
                          char_type fill, const std::tm* t,

                          char format, char modifier ) const;
(3)

Converts the calendar date and time stored in the std::tm object pointed to by t into a character string, according to the format string [fmtbeg, fmtend). The format string is the same as used by std::srtftime, but each format specifier is processed by an individual call to do_put(), which can be customized by extending this facet.

1) Steps through the character sequence [fmtbeg, fmtend), examining the characters. Every character that is not a part of a format sequence is written to the output iterator out immediately. To identify format sequences, this function narrows the next character c in [fmtbeg, fmtend) as if by std::ctype<char_type>(str.getloc()).narrow(c,0) and if it equals '%', the next one or two characters are compared to the list of format sequences recognized by std::strftime plus any additional implementation-defined formats supported by this locale. For each valid format sequence, a call to do_put(out, str, fill, t, format, modifier) is made, where format is the format sequence character, and modifier is the optional format sequence modifier ('E' or 'O'). A value of '\0' is used if the modifier is absent.
2) Calls the do_put member function of the most derived class.
3) Converts the calendar date and time stored in the std::tm object pointed to by t into a character string, according to the format conversion sequence formed by concatenating '%', the value of modifier if not '\0', and the value of format. The format is interpreted the same way as the function std::strftime, except that the formats that are described as locale-dependent are defined by this locale, and additional format specifiers may be supported (the fill argument is provided for these implementation-defined format specifiers to use). The string is written to the output iterator out.

Contents

[edit] Parameters

out - output iterator where the result of the conversion is written
str - a stream object that this function uses to obtain locale facets when needed, e.g. std::ctype to narrow characters
t - pointer to the std::tm object from which the date/time values are obtained
fmtbeg - pointer to the first character of a sequence of char_type characters specifying the conversion format

The format string consists of zero or more conversion specifiers and ordinary characters (except %). All ordinary characters, including the terminating null character, are copied to the output string without modification. Each conversion specification begins with % character, optionally followed by E or O modifier (ignored if unsupported by the locale), followed by the character that determines the behavior of the specifier. The following format specifiers are available:

Conversion
specifier
Explanation Used fields
% writes literal %. The full conversion specification must be %%.
n
(C++11)
writes newline character
t
(C++11)
writes horizontal tab character
Year
Y writes year as a 4 digit decimal number tm_year
EY
(C++11)
writes year in the alternative representation, e.g.平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale tm_year
y writes last 2 digits of year as a decimal number (range [00,99]) tm_year
Oy
(C++11)
writes last 2 digits of year using the alternative numeric system, e.g. 十一 instead of 11 in ja_JP locale tm_year
Ey
(C++11)
writes year as offset from locale's alternative calendar period %EC (locale-dependent) tm_year
C
(C++11)
writes first 2 digits of year as a decimal number (range [00,99]) tm_year
EC
(C++11)
writes name of the base year (period) in the locale's alternative representation, e.g. 平成 (Heisei era) in ja_JP tm_year
G
(C++11)
writes ISO 8601 week-based year, i.e. the year that contains the specified week.

In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:

  • Includes January 4
  • Includes first Thursday of the year
tm_year, tm_wday, tm_yday
g
(C++11)
writes last 2 digits of ISO 8601 week-based year, i.e. the year that contains the specified week (range [00,99]).

In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:

  • Includes January 4
  • Includes first Thursday of the year
tm_year, tm_wday, tm_yday
Month
b writes abbreviated month name, e.g. Oct (locale dependent) tm_mon
h
(C++11)
synonym of b tm_mon
B writes full month name, e.g. October (locale dependent) tm_mon
m writes month as a decimal number (range [01,12]) tm_mon
Om
(C++11)
writes month using the alternative numeric system, e.g. 十二 instead of 12 in ja_JP locale tm_mon
Week
U writes week of the year as a decimal number (Sunday is the first day of the week) (range [00,53]) tm_year, tm_wday, tm_yday
OU
(C++11)
writes week of the year, as by %U, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
W writes week of the year as a decimal number (Monday is the first day of the week) (range [00,53]) tm_year, tm_wday, tm_yday
OW
(C++11)
writes week of the year, as by %W, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
V
(C++11)
writes ISO 8601 week of the year (range [01,53]).

In IS0 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:

  • Includes January 4
  • Includes first Thursday of the year
tm_year, tm_wday, tm_yday
OV
(C++11)
writes week of the year, as by %V, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
Day of the year/month
j writes day of the year as a decimal number (range [001,366]) tm_yday
d writes day of the month as a decimal number (range [01,31]) tm_mday
Od
(C++11)
writes zero-based day of the month using the alternative numeric system, e.g 二十七 instead of 23 in ja_JP locale

Single character is preceded by a space.

tm_mday
e
(C++11)
writes day of the month as a decimal number (range [1,31]).

Single digit is preceded by a space.

tm_mday
Oe
(C++11)
writes one-based day of the month using the alternative numeric system, e.g. 二十七 instead of 27 in ja_JP locale

Single character is preceded by a space.

tm_mday
Day of the week
a writes abbreviated weekday name, e.g. Fri (locale dependent) tm_wday
A writes full weekday name, e.g. Friday (locale dependent) tm_wday
w writes weekday as a decimal number, where Sunday is 0 (range [0-6]) tm_wday
Ow
(C++11)
writes weekday, where Sunday is 0, using the alternative numeric system, e.g. 二 instead of 2 in ja_JP locale tm_wday
u
(C++11)
writes weekday as a decimal number, where Monday is 1 (ISO 8601 format) (range [1-7]) tm_wday
Ou
(C++11)
writes weekday, where Monday is 1, using the alternative numeric system, e.g. 二 instead of 2 in ja_JP locale tm_wday
Hour, minute, second
H writes hour as a decimal number, 24 hour clock (range [00-23]) tm_hour
OH
(C++11)
writes hour from 24-hour clock using the alternative numeric system, e.g. 十八 instead of 18 in ja_JP locale tm_hour
I writes hour as a decimal number, 12 hour clock (range [01,12]) tm_hour
OI
(C++11)
writes hour from 12-hour clock using the alternative numeric system, e.g. 六 instead of 06 in ja_JP locale tm_hour
M writes minute as a decimal number (range [00,59]) tm_min
OM
(C++11)
writes minute using the alternative numeric system, e.g. 二十五 instead of 25 in ja_JP locale tm_min
S writes second as a decimal number (range [00,60]) tm_sec
OS
(C++11)
writes second using the alternative numeric system, e.g. 二十四 instead of 24 in ja_JP locale tm_sec
Other
c writes standard date and time string, e.g. Sun Oct 17 04:41:13 2010 (locale dependent) all
Ec
(C++11)
writes alternative date and time string, e.g. using 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all
x writes localized date representation (locale dependent) all
Ex
(C++11)
writes alternative date representation, e.g. using 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all
X writes localized time representation (locale dependent) all
EX
(C++11)
writes alternative time representation (locale dependent) all
D
(C++11)
equivalent to "%m/%d/%y" tm_mon, tm_mday, tm_year
F
(C++11)
equivalent to "%Y-%m-%d" (the ISO 8601 date format) tm_mon, tm_mday, tm_year
r
(C++11)
writes localized 12-hour clock time (locale dependent) tm_hour, tm_min, tm_sec
R
(C++11)
equivalent to "%H:%M" tm_hour, tm_min
T
(C++11)
equivalent to "%H:%M:%S" (the ISO 8601 time format) tm_hour, tm_min, tm_sec
p writes localized a.m. or p.m. (locale dependent) tm_hour
z
(C++11)
writes offset from UTC in the ISO 8601 format (e.g. -0430), or no characters if the time zone information is not available tm_isdst
Z writes time zone name or abbreviation, or no characters if the time zone information is not available (locale dependent) tm_isdst


fmtend - pointer one past the last character of a sequence of char_type characters specifying the conversion format
fill - fill character (usually space)
format - the character that names a conversion specifier
modifier - the optional modifier that may appear between % and the conversion specifier

[edit] Return value

Iterator pointing one past the last character that was produced .

[edit] Notes

No error handling is provided.

The fill character is provided for those implementation-defined format specifiers and for the user-defined overrides of do_put() that use padding and filling logic. Such implementations typically make use of the formatting flags from str.

[edit] Example

#include <iostream>
#include <sstream>
#include <iomanip>
#include <ctime>
 
void try_time_put(const std::tm* t, const std::string& fmt)
{
        std::cout.imbue(std::locale());
        std::cout << "In the locale '" << std::cout.getloc().name() << "' : '";
 
        std::use_facet<std::time_put<char>>(std::cout.getloc()).put(
                    std::ostreambuf_iterator<char>(std::cout),
                    std::cout, ' ', t, &fmt[0], &fmt[0] + fmt.size());
 
        std::cout << "'\n";
}
 
int main()
{
    std::time_t t = std::time(NULL);
    std::tm tm = *std::localtime(&t);
 
    std::string fmt = "%c";
    std::cout << "Using the format string '" << fmt
              << "' to format the time: " << std::ctime(&t) << '\n';
 
    std::locale::global(std::locale("de_DE.utf8"));
    try_time_put(&tm, fmt);
 
    std::locale::global(std::locale("el_GR.utf8"));
    try_time_put(&tm, fmt);
 
    std::locale::global(std::locale("ja_JP.utf8"));
    try_time_put(&tm, fmt);
}

Output:

Using the format string '%c' to format the time: Mon Feb 11 22:58:50 2013
 
In the locale 'de_DE.utf8' : 'Mo 11 Feb 2013 23:02:38 EST'
In the locale 'el_GR.utf8' : 'Δευ 11 Φεβ 2013 11:02:38 μμ EST'
In the locale 'ja_JP.utf8' : '2013年02月11日 23時02分38秒'

[edit] See also

(C++11)
formats and outputs a date/time value according to the specified format
(function template) [edit]
[virtual] (C++11)
extracts date/time components from input stream, according to the specified format
(virtual protected member function of std::time_get) [edit]