NAME¶

std::chrono::operator<<(std::chrono::weekday) - std::chrono::operator<<(std::chrono::weekday)

Synopsis¶

Defined in header <chrono>
template< class CharT, class Traits >

std::basic_ostream<CharT, Traits>& (since C++20)

operator<<( std::basic_ostream<CharT, Traits>& os, const
std::chrono::weekday& wd );

If !wd.ok(), inserts wd.c_encoding() followed by " is not a valid weekday" into os.
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.

Equivalent to

return os << (wd.ok() ?
std::format(os.getloc(), STATICALLY_WIDEN<CharT>("{:L%a}"), wd) :
std::format(os.getloc(), STATICALLY_WIDEN<CharT>("{} is not a valid weekday"),
wd.c_encoding()));

where STATICALLY_WIDEN<CharT>("...") is "..." if CharT is char, and L"..." if CharT
is wchar_t.

Return value¶

os.

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
P2372R3 C++20 the given locale was used by default L is needed to use the given
locale

See also¶

format stores formatted representation of the
(C++20) arguments in a new string
(function template)
std::formatter<std::chrono::weekday> specialization of std::formatter that formats a
(C++20) weekday according to the provided format
(class template specialization)