std::get_time

 

C++

Compiler support

Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Input/output library

I/O manipulators

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

basic_spanbuf (C++23)

strstreambuf (deprecated in C++98)

basic_syncbuf (C++20)

Streams

Abstractions

ios_base

basic_ios

basic_istream

basic_ostream

basic_iostream

File I/O

basic_ifstream

basic_ofstream

basic_fstream

String I/O

basic_istringstream

basic_ostringstream

basic_stringstream

Array I/O

basic_ispanstream (C++23)

basic_ospanstream (C++23)

basic_spanstream (C++23)

istrstream (deprecated in C++98)

ostrstream (deprecated in C++98)

strstream (deprecated in C++98)

Synchronized Output

basic_osyncstream (C++20)

Types

streamoff

streamsize

fpos

Error category interface

iostream_category (C++11)

io_errc (C++11)

 

Input/output manipulators

Floating-point formatting
showpointnoshowpoint setprecision	fixedscientifichexfloatdefaultfloat (C++11)(C++11)
Integer formatting
setbase showbasenoshowbase	dechexoct
Boolean formatting
boolalphanoboolalpha
Field width and fill control
setfill setw	internalleftright
Other formatting
showposnoshowpos	uppercasenouppercase
Whitespace processing
ws ends	skipwsnoskipws
Output flushing
flush endl flush_emit (C++20)	unitbufnounitbuf emit_on_flushnoemit_on_flush (C++20)(C++20)
Status flags manipulation
resetiosflags	setiosflags
Time and money I/O
get_money (C++11) get_time (C++11)	put_money (C++11) put_time (C++11)
Quoted manipulator
quoted (C++14)

 

Defined in header <iomanip>
template< class CharT > /*unspecified*/ get_time( std::tm* tmb, const CharT* fmt );		(since C++11)

When used in an expression in >> get_time(tmb, fmt), parses the character input as a date/time value according to format string fmt according to the std::time_get facet of the locale currently imbued in the input stream in. The resultant value is stored in a std::tm object pointed to by tmb.

Parameters

tmb	-	valid pointer to the std::tm object where the result will be stored
fmt	-	pointer to a null-terminated CharT string specifying the conversion format The format string consists of zero or more conversion specifiers, whitespace characters, and ordinary characters (except %). Each ordinary character is expected to match one character in the input stream in case-insensitive comparison. Each whitespace character matches arbitrary whitespace in the input string. 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 format specifiers match the POSIX function strptime(): Conversion specifier Explanation Writes to fields % matches a literal %. The full conversion specification must be %%. (none) t matches any whitespace. (none) n matches any whitespace. (none) Year Y parses full year as a 4 digit decimal number, leading zeroes permitted but not required tm_year EY parses year in the alternative representation, e.g.平成23年 (year Heisei 23) which writes 2011 to tm_year in ja_JP locale tm_year y parses last 2 digits of year as a decimal number. Range [69,99] results in values 1969 to 1999, range [00,68] results in 2000-2068 tm_year Oy parses last 2 digits of year using the alternative numeric system, e.g. 十一 is parsed as 11 in ja_JP locale tm_year Ey parses year as offset from locale's alternative calendar period %EC tm_year C parses the first 2 digits of year as a decimal number (range [00,99]) tm_year EC parses the name of the base year (period) in the locale's alternative representation, e.g. 平成 (Heisei era) in ja_JP tm_year Month b parses the month name, either full or abbreviated, e.g. Oct tm_mon h synonym of b tm_mon B synonym of b tm_mon m parses the month as a decimal number (range [01,12]), leading zeroes permitted but not required tm_mon Om parses the month using the alternative numeric system, e.g. 十二 parses as 12 in ja_JP locale tm_mon Week U parses the week of the year as a decimal number (Sunday is the first day of the week) (range [00,53]), leading zeroes permitted but not required tm_year, tm_wday, tm_yday OU parses the week of the year, as by %U, using the alternative numeric system, e.g. 五十二 parses as 52 in ja_JP locale tm_year, tm_wday, tm_yday W parses the week of the year as a decimal number (Monday is the first day of the week) (range [00,53]), leading zeroes permitted but not required tm_year, tm_wday, tm_yday OW parses the week of the year, as by %W, using the alternative numeric system, e.g. 五十二 parses as 52 in ja_JP locale tm_year, tm_wday, tm_yday Day of the year/month j parses day of the year as a decimal number (range [001,366]), leading zeroes permitted but not required tm_yday d parses the day of the month as a decimal number (range [01,31]), leading zeroes permitted but not required tm_mday Od parses the day of the month using the alternative numeric system, e.g 二十七 parses as 27 in ja_JP locale, leading zeroes permitted but not required tm_mday e synonym of d tm_mday Oe synonym of Od tm_mday Day of the week a parses the name of the day of the week, either full or abbreviated, e.g. Fri tm_wday A synonym of a tm_wday w parses weekday as a decimal number, where Sunday is 0 (range [0-6]) tm_wday Ow parses weekday as a decimal number, where Sunday is 0, using the alternative numeric system, e.g. 二 parses as 2 in ja_JP locale tm_wday Hour, minute, second H parses the hour as a decimal number, 24 hour clock (range [00-23]), leading zeroes permitted but not required tm_hour OH parses hour from 24-hour clock using the alternative numeric system, e.g. 十八 parses as 18 in ja_JP locale tm_hour I parses hour as a decimal number, 12 hour clock (range [01,12]), leading zeroes permitted but not required tm_hour OI parses hour from 12-hour clock using the alternative numeric system, e.g. 六 reads as 06 in ja_JP locale tm_hour M parses minute as a decimal number (range [00,59]), leading zeroes permitted but not required tm_min OM parses minute using the alternative numeric system, e.g. 二十五 parses as 25 in ja_JP locale tm_min S parses second as a decimal number (range [00,60]), leading zeroes permitted but not required tm_sec OS parses second using the alternative numeric system, e.g. 二十四 parses as 24 in ja_JP locale tm_sec Other c parses the locale's standard date and time string format, e.g. Sun Oct 17 04:41:13 2010 (locale dependent) all Ec parses the locale's alternative date and time string format, e.g. expecting 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all x parses the locale's standard date representation all Ex parses the locale's alternative date representation, e.g. expecting 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all X parses the locale's standard time representation all EX parses the locale's alternative time representation all D equivalent to "%m / %d / %y " tm_mon, tm_mday, tm_year r parses locale's standard 12-hour clock time (in POSIX, "%I : %M : %S %p") tm_hour, tm_min, tm_sec R equivalent to "%H : %M" tm_hour, tm_min T equivalent to "%H : %M : %S" tm_hour, tm_min, tm_sec p parses the locale's equivalent of a.m. or p.m. tm_hour Note: tm_isdst is not written to, and needs to be set explicitly for use with functions such as mktime

Return value

Returns an object of unspecified type such that if in is the name of an input stream of type std::basic_istream<CharT, Traits>, then the expression in >> get_time(tmb, fmt) behaves as if the following code was executed:

typedef std::istreambuf_iterator<CharT, Traits> Iter;
typedef std::time_get<CharT, Iter> TimeGet;
std::ios_base::iostate err = std::ios_base::goodbit;
const TimeGet& tg = std::use_facet<TimeGet>(in.getloc());
tg.get(Iter(in.rdbuf()), Iter(), in, err, tmb, fmt, fmt + traits::length(fmt));
if (err != std::ios_base::goodbit)
    in.setstate(err);

Notes

As specified in std::time_get::do_get, which this function calls, it's unspecified if this function zero out the fields in *tmb that are not set directly by the conversion specifiers that appear in fmt: portable programs should initialize every field of *tmb to zero before calling std::get_time.

Example

note: choose clang to observe the output. libstdc++ does not correctly implement the %b specifier: bug 78714

Run this code

#include <iostream>
#include <sstream>
#include <locale>
#include <iomanip>
 
int main()
{
    std::tm t = {};
    std::istringstream ss("2011-Februar-18 23:12:34");
    ss.imbue(std::locale("de_DE.utf-8"));
    ss >> std::get_time(&t, "%Y-%b-%d %H:%M:%S");
    if (ss.fail()) {
        std::cout << "Parse failed\n";
    } else {
        std::cout << std::put_time(&t, "%c") << '\n';
    }
}

Possible output:

Sun Feb 18 23:12:34 2011

See also

time_get	parses time/date values from an input character sequence into struct std::tm (class template)
put_time (C++11)	formats and outputs a date/time value according to the specified format (function template)
parse (C++20)	parses a chrono object from a stream (function template)