# std::chrono::operator<< (std::chrono::year)

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< cpp‎ | chrono‎ | year

template <class CharT, class Traits> std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const std::chrono::year& y); |  | (since C++20)

Forms a `std::basic_string<CharT>` `s` consisting of the year value stored in `y` formatted as a decimal number, left-padded with `0` to four digits if the result would otherwise be less than four digits. Inserts that string into `os`. Then, if !y.ok(), inserts the string " is not a valid year" into `os`.

### Return value

`os`.

### Notes

This `operator<<` is primarily intended for debugging use. For control over formatting, use std::chrono::format.

### See also

format (C++20) | formats a streamable `chrono` object for insertion (function template)
to_stream | outputs a `year` into a stream according to the provided format (function template)

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