std::time_get::get_year
Defined in header <locale> | | |
|---|---|---|
public: iter_type do_get_year( iter_type s, iter_type end, std::ios_base& str, std::ios_base::iostate& err, std::tm* t) const; | (1) | |
protected: virtual iter_type do_get_year( iter_type s, iter_type end, std::ios_base& str, std::ios_base::iostate& err, std::tm* t) const; | (2) | |
1%29公共成员函数，调用受保护的虚拟成员函数。do_get_year最派生的类。
2%29从序列中读取连续字符。[beg, end)并使用一些实现定义的格式分析了一年。根据地区的不同，可以接受两位数的年份，并且实现定义了它们属于哪个世纪。
分析的年份存储在std::tm结构场t->tm_year...
如果在读取有效日期之前到达结束迭代器，则函数设置std::ios_base::eofbit在err如果遇到解析错误，则函数将std::ios_base::failbit在err...
参数
beg | - | iterator designating the start of the sequence to parse |
|---|---|---|
end | - | one past the end iterator for the sequence to parse |
str | - | a stream object that this function uses to obtain locale facets when needed, e.g. std::ctype to skip whitespace or std::collate to compare strings |
err | - | stream error flags object that is modified by this function to indicate errors |
t | - | pointer to the std::tm object that will hold the result of this function call |
返回值
中的最后一个字符[beg, end)这被确认为有效年份的一部分。
注记
对于两位数的输入值，许多实现使用与转换说明符相同的解析规则。'%y'如std::get_time，，，std::time_get::get()，以及POSIX函数strptime()：：两位数的整数，在范围内的值。69，99结果值为1969至1999，范围00682000至2068年度结果。四位数字输入通常被接受为-原样.
如果遇到解析错误，则此函数的大多数实现将离开。*t未经修改。
例
二次
#include <iostream>
#include <locale>
#include <sstream>
#include <iterator>
void try_get_year(const std::string& s)
{
std::cout << "Parsing the year out of '" << s <<
"' in the locale " << std::locale().name() << '\n';
std::istringstream str(s);
std::ios_base::iostate err = std::ios_base::goodbit;
std::tm t;
std::istreambuf_iterator<char> ret =
std::use_facet<std::time_get<char>>(str.getloc()).get_year(
std::istreambuf_iterator<char>(str),
std::istreambuf_iterator<char>(),
str, err, &t
);
str.setstate(err);
if (str) {
std::cout << "Successfully parsed, year is " << 1900 + t.tm_year;
if (ret != std::istreambuf_iterator<char>()) {
std::cout << " Remaining content: ";
std::copy(ret, std::istreambuf_iterator<char>(),
std::ostreambuf_iterator<char>(std::cout));
} else {
std::cout << " the input was fully consumed";
}
} else {
std::cout << "Parse failed. Unparsed string: ";
std::copy(ret, std::istreambuf_iterator<char>(),
std::ostreambuf_iterator<char>(std::cout));
}
std::cout << '\n';
}
int main()
{
std::locale::global(std::locale("en_US.utf8"));
try_get_year("13");
try_get_year("2013");
std::locale::global(std::locale("ja_JP.utf8"));
try_get_year("2013年");
}二次
可能的产出：
二次
Parsing the year out of '13' in the locale en_US.utf8
Successfully parsed, year is 2013 the input was fully consumed
Parsing the year out of '2013' in the locale en_US.utf8
Successfully parsed, year is 2013 the input was fully consumed
Parsing the year out of '2013年' in the locale ja_JP.utf8
Successfully parsed, year is 2013 Remaining content: 年二次
另见
get_time (C++11) | parses a date/time value of specified format (function template) |
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