Utilities library
Language support
Type support (basic types, RTTI)
Library feature-test macros (C++20)
Dynamic memory management
Program utilities
Coroutine support (C++20)
Variadic functions
Debugging support
Three-way comparison
General utilities
Date and time
Function objects
Formatting library (C++20)
Relational operators (deprecated in C++20)
Integer comparison functions
Swap and type operations
Common vocabulary types
Elementary string conversions

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

std::basic_ostream<CharT, Traits>&
    operator<<( std::basic_ostream<CharT, Traits>& os,

                const std::chrono::weekday_indexed& wdi );
(since C++20)

Outputs a textual representation of wdi into the stream os, as if by:

if (wdi.index() >=1 && wdi.index() <= 5)
    os << std::format(os.getloc(), STATICALLY_WIDEN<CharT>("{:L}[{}]"),
                      wdi.weekday(), wdi.index());
    os << std::format(os.getloc(), STATICALLY_WIDEN<CharT>("{:L}[{} is not a valid index]"),
                      wdi.weekday(), wdi.index());

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

[edit] Return value


[edit] 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

[edit] See also

stores formatted representation of the arguments in a new string
(function template) [edit]
formatting support for weekday
(class template specialization) [edit]