std::chrono::weekday::operator++, std::chrono::weekday::operator--

constexpr std::chrono::weekday& operator++() noexcept;
(1) (since C++20)
constexpr std::chrono::weekday operator++(int) noexcept;
(2) (since C++20)
constexpr std::chrono::weekday& operator--() noexcept;
(3) (since C++20)
constexpr std::chrono::weekday operator--(int) noexcept;
(4) (since C++20)

Adds or subtracts 1 from the weekday value, reducing the result modulo 7 to an integer in the range [0, 6].

1-2) Performs *this += std::chrono::days{1};
3-4) Performs *this -= std::chrono::days{1};



Return value

1,3) a reference to this weekday after modification
2,4) a copy of the weekday made before modification


After a call to one of these functions, ok() is always true.


#include <iostream>
#include <chrono>
int main()
    std::cout << std::boolalpha;
    std::chrono::weekday wd {0}; // Sunday is 0 or 7
    std::cout << (wd == std::chrono::Saturday) << ' ';
    std::cout << (wd == std::chrono::Sunday) << '\n';


true true

See also

adds or subtracts a number of days
(public member function)
performs arithmetic on weekdays

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