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Difference between revisions of "cpp/locale/time get"

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< cpp‎ | locale
(c -> c/core.)
m (fmt, ., headers sorted)
 
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{{inheritance diagram/std-time_get}}
 
{{inheritance diagram/std-time_get}}
  
−
===Type requirements===
+
If a {{tt|std::time_get}} specialization is not guaranteed to be provided by the standard library (see below), the behaviors of its member functions (except the constructor and destructor) are not guaranteed as specified.
−
{{par begin}}
+
−
{{par req named | InputIt | InputIterator}}
+
−
{{par end}}
+
  
 
===Specializations===
 
===Specializations===
−
Two standalone (locale-independent) full specializations and two partial specializations are provided by the standard library:
+
The standard library is guaranteed to provide the following specializations (they are {{rlp|locale|required to be implemented by any locale object}}):
 
{{dsc begin}}
 
{{dsc begin}}
−
{{dsc header | locale }}
+
{{dsc header|locale}}
−
{{dsc | {{c/core|std::time_get<char>}} | parses narrow string representations of date and time }}
+
{{dsc|{{c/core|std::time_get<char>}}|parses narrow string representations of date and time}}
−
{{dsc | {{c/core|std::time_get<wchar_t>}} | parses wide string representations of date and time }}
+
{{dsc|{{c/core|std::time_get<wchar_t>}}|parses wide string representations of date and time}}
−
{{dsc | {{c/core|std::time_get<char, InputIt>}} | parses narrow string representations of date and time using custom input iterator}}
+
−
{{dsc | {{c/core|std::time_get<wchar_t, InputIt>}} | parses wide string representations of date and time using custom input iterator}}
+
 
{{dsc end}}
 
{{dsc end}}
−
In addition, every locale object constructed in a C++ program implements its own (locale-specific) versions of these specializations.
+
 
 +
In addition, the standard library is also guaranteed to provide every specialization that satisfies the following type requirements:
 +
* {{tt|CharT}} is one of {{c/core|char}} and {{c/core|wchar_t}}, and
 +
* {{tt|InputIt}} must meet the requirements of {{named req|InputIterator}}.
  
 
===Member types===
 
===Member types===
 
{{dsc begin}}
 
{{dsc begin}}
−
{{dsc hitem | Member type | Definition}}
+
{{dsc hitem|Member type|Definition}}
−
{{dsc | {{tt|char_type}} | {{tt|CharT}}}}
+
{{dsc|{{tt|char_type}}|{{tt|CharT}}}}
−
{{dsc | {{tt|iter_type}} | {{tt|InputIt}}}}
+
{{dsc|{{tt|iter_type}}|{{tt|InputIt}}}}
 
{{dsc end}}
 
{{dsc end}}
  
 
===Member functions===
 
===Member functions===
 
{{dsc begin}}
 
{{dsc begin}}
−
{{dsc mem ctor | cpp/locale/time_get/time_get | constructs a new {{tt|time_get}} facet }}
+
{{dsc mem ctor|cpp/locale/time_get/time_get|constructs a new {{tt|time_get}} facet}}
−
{{dsc prot mem dtor | cpp/locale/time_get/~time_get | destructs a {{tt|time_get}} facet }}
+
{{dsc prot mem dtor|cpp/locale/time_get/~time_get|destructs a {{tt|time_get}} facet}}
−
{{dsc inc | cpp/locale/time_get/dsc date_order}}
+
{{dsc inc|cpp/locale/time_get/dsc date_order}}
−
{{dsc inc | cpp/locale/time_get/dsc get_time}}
+
{{dsc inc|cpp/locale/time_get/dsc get_time}}
−
{{dsc inc | cpp/locale/time_get/dsc get_date}}
+
{{dsc inc|cpp/locale/time_get/dsc get_date}}
−
{{dsc inc | cpp/locale/time_get/dsc get_weekday}}
+
{{dsc inc|cpp/locale/time_get/dsc get_weekday}}
−
{{dsc inc | cpp/locale/time_get/dsc get_monthname}}
+
{{dsc inc|cpp/locale/time_get/dsc get_monthname}}
−
{{dsc inc | cpp/locale/time_get/dsc get_year}}
+
{{dsc inc|cpp/locale/time_get/dsc get_year}}
−
{{dsc inc | cpp/locale/time_get/dsc get}}
+
{{dsc inc|cpp/locale/time_get/dsc get}}
 
{{dsc end}}
 
{{dsc end}}
  
 
===Member objects===
 
===Member objects===
 
{{dsc begin}}
 
{{dsc begin}}
−
{{dsc mem obj | nolink=true | {{dsc small|static std::locale::id}} id | ''id'' of the locale }}
+
{{dsc mem obj|nolink=true|{{dsc small|static std::locale::id}} id|''id'' of the locale}}
 
{{dsc end}}
 
{{dsc end}}
  
 
===Protected member functions===
 
===Protected member functions===
 
{{dsc begin}}
 
{{dsc begin}}
−
{{dsc inc | cpp/locale/time_get/dsc do_date_order}}
+
{{dsc inc|cpp/locale/time_get/dsc do_date_order}}
−
{{dsc inc | cpp/locale/time_get/dsc do_get_time}}
+
{{dsc inc|cpp/locale/time_get/dsc do_get_time}}
−
{{dsc inc | cpp/locale/time_get/dsc do_get_date}}
+
{{dsc inc|cpp/locale/time_get/dsc do_get_date}}
−
{{dsc inc | cpp/locale/time_get/dsc do_get_weekday}}
+
{{dsc inc|cpp/locale/time_get/dsc do_get_weekday}}
−
{{dsc inc | cpp/locale/time_get/dsc do_get_monthname}}
+
{{dsc inc|cpp/locale/time_get/dsc do_get_monthname}}
−
{{dsc inc | cpp/locale/time_get/dsc do_get_year}}
+
{{dsc inc|cpp/locale/time_get/dsc do_get_year}}
−
{{dsc inc | cpp/locale/time_get/dsc do_get}}
+
{{dsc inc|cpp/locale/time_get/dsc do_get}}
 
{{dsc end}}
 
{{dsc end}}
  
−
{{ inherited | {{small|std::}}time_base |
+
{{inherited|{{small|std::}}time_base|
 
{{dsc begin}}
 
{{dsc begin}}
−
{{dsc hitem | Type | Definition}}
+
{{dsc hitem|Type|Definition}}
−
{{dsc | {{tt|dateorder}} | date order enumeration type, defining the values {{tt|no_order}}, {{tt|dmy}}, {{tt|mdy}}, {{tt|ymd}}, and {{tt|ydm}}}}
+
{{dsc|{{tt|dateorder}}|date order enumeration type, defining the values {{tt|no_order}}, {{tt|dmy}}, {{tt|mdy}}, {{tt|ymd}}, and {{tt|ydm}}}}
 
{{dsc end}}
 
{{dsc end}}
 
}}
 
}}
Line 76: Line 74:
 
===Example===
 
===Example===
 
{{example
 
{{example
−
|1=Note: choose clang to observe the output. libstdc++ does not correctly implement the %b specifier: [https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78714 bug 78714]
+
|1=Note: choose clang to observe the output. libstdc++ does not correctly implement the %b specifier: [https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78714 bug 78714].
 
|code=
 
|code=
 +
#include <iomanip>
 
#include <iostream>
 
#include <iostream>
 +
#include <locale>
 
#include <sstream>
 
#include <sstream>
−
#include <locale>
 
−
#include <iomanip>
 
  
 
int main()
 
int main()

Latest revision as of 09:31, 6 October 2023

 
C++
 
Localization library
 
std::time_get
 
Defined in header <locale>
template<

    class CharT,
    class InputIt = std::istreambuf_iterator<CharT>

> class time_get;

Class template std::time_get encapsulates date and time parsing rules. The I/O manipulator std::get_time uses the std::time_get facet of the I/O stream's locale to convert text input to a std::tm object.

cpp/locale/time basecpp/locale/locale/facetstd-time get-inheritance.svg

Inheritance diagram

If a std::time_get specialization is not guaranteed to be provided by the standard library (see below), the behaviors of its member functions (except the constructor and destructor) are not guaranteed as specified.

Contents

[edit] Specializations

The standard library is guaranteed to provide the following specializations (they are required to be implemented by any locale object):

Defined in header <locale>
std::time_get<char> parses narrow string representations of date and time
std::time_get<wchar_t> parses wide string representations of date and time

In addition, the standard library is also guaranteed to provide every specialization that satisfies the following type requirements:

  • CharT is one of char and wchar_t, and
  • InputIt must meet the requirements of LegacyInputIterator.

[edit] Member types

Member type Definition
char_type CharT
iter_type InputIt

[edit] Member functions

 constructs a new time_get facet
(public member function)
destructs a time_get facet
(protected member function)
invokes do_date_order
(public member function) [edit]
invokes do_get_time
(public member function) [edit]
invokes do_get_date
(public member function) [edit]
invokes do_get_weekday
(public member function) [edit]
invokes do_get_monthname
(public member function) [edit]
invokes do_get_year
(public member function) [edit]
(C++11)
 invokes do_get
(public member function) [edit]

[edit] Member objects

static std::locale::id id
 id of the locale
(public member object)

[edit] Protected member functions

[virtual]
 obtains preferred ordering of day, month, and year
(virtual protected member function) [edit]
[virtual]
 extracts hours, minutes, and seconds from input stream
(virtual protected member function) [edit]
[virtual]
 extracts month, day, and year from input stream
(virtual protected member function) [edit]
[virtual]
 extracts the name of a day of the week from input stream
(virtual protected member function) [edit]
[virtual]
 extracts a month name from input stream
(virtual protected member function) [edit]
[virtual]
 extracts a year from input stream
(virtual protected member function) [edit]
[virtual] (C++11)
 extracts date/time components from input stream, according to the specified format
(virtual protected member function) [edit]

Inherited from std::time_base

Type Definition
dateorder date order enumeration type, defining the values no_order, dmy, mdy, ymd, and ydm

[edit] Example

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

Run this code
#include <iomanip>
#include <iostream>
#include <locale>
#include <sstream>
 
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

[edit] See also

 formats contents of std::tm for output as character sequence
(class template) [edit]
(C++11)
 parses a date/time value of specified format
(function template) [edit]
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