std::time_get<CharT,InputIt>:: get, std::time_get<CharT,InputIt>:: do_get

In the body of the loop, the following steps take place:

First, clears the error bits in err by executing err = std:: ios_base :: goodbit . Then reads characters from the input sequence [ beg, end ) that are expected by the std::time_get format specifier formed by combining '%' , modifier (if not ' \0 ' ), and format . If the characters do not combine to form a valid conversion specifier, sets failbit in err . If the end of the input stream is reached after reading a character, sets eofbit in err . If the input string was parsed successfully, updates the corresponding fields of * t .

For complex conversion specifiers, such as '%x' or '%c' , or the directives that use the modifiers 'E' and 'O' , the function may fail to determine some of the values to store in * t . In such case, it sets eofbit in err and leaves these fields in unspecified state.

Parameters

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() :

Note: tm_isdst is not written to, and needs to be set explicitly for use with functions such as mktime

Return value

Iterator pointing one past the last character in [ beg, end ) that was parsed successfully.

Notes

The case-insensitive comparison for the non-whitespace non- '%' characters in the format string, the std::collate facet of the locale provided by str is typically, but not necessarily, used.

If a parsing error is encountered, many implementations of this function leave * t completely untouched.

It's unspecified if these functions zero out the fields in * t that they do not set directly: portable programs should initialize every field to zero before calling get() .

Example

#include <iomanip>
#include <iostream>
#include <locale>
#include <sstream>
 
int main()
{
    std::istringstream ss("2026-März-12 23:45:56");
    ss.imbue(std::locale("de_DE.utf8"));
 
    auto& f = std::use_facet<std::time_get<char>>(ss.getloc());
    std::tm t{};
    std::string s = "%Y-%b-%d %H:%M:%S";
    std::ios_base::iostate err = std::ios_base::goodbit;
    auto ret = f.get({ss}, {}, ss, err, &t, &s[0], &s[0] + s.size());
    ss.setstate(err);
    std::istreambuf_iterator<char> last{};
 
    if (ss)
    {
        std::cout << "Successfully parsed as " << std::put_time(&t, "%c") << '\n';
        if (ret != last)
        {
            std::cout << "Remaining content: ";
            std::copy(ret, last, std::ostreambuf_iterator<char>(std::cout));
        }
        else
            std::cout << "The input was fully consumed.";
    }
    else
    {
        std::cout << "Parse failed.\nUnparsed string: ";
        std::copy(ret, last, std::ostreambuf_iterator<char>(std::cout));
    }
    std::cout << '\n';
}

Successfully parsed as Sun Mar 12 23:45:56 2026
The input was fully consumed.

See also