std::chrono::operator<< (std::chrono::weekday)
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                    | template <class CharT, class Traits> std::basic_ostream<CharT, Traits>& | (since C++20) | |
If !wd.ok(), equivalent to os << unsigned(wd) << " is not a valid weekday";. Otherwise, forms a std::basic_string<CharT> s consisting of the abbreviated weekday name for the weekday represented by wd, determined using the locale associated with os, and inserts s into os.
Return value
os.
Notes
This operator<< is primarily intended for debugging use. For control over formatting, use std::chrono::format.
See also
| (C++20) | formats a streamable chronoobject for insertion(function template) | 
| outputs a weekdayinto a stream according to the provided format(function template) |