std::chrono::weekday_indexed::ok -
std::chrono::weekday_indexed::ok
constexpr bool ok() const noexcept; (since C++20)
Checks if the weekday object and the index stored in *this are both
valid.
true if weekday().ok() == true and index() is in the range [1,
5]. Otherwise false.
// Run this code
#include <iostream>
#include <chrono>
int main()
{
std::cout << std::boolalpha;
std::chrono::weekday_indexed wdi {std::chrono::Tuesday[2]};
std::cout << (wdi.ok()) << ' ';
wdi = {std::chrono::weekday(42)[2]};
std::cout << (wdi.ok()) << ' ';
wdi = {std::chrono::Tuesday[-4]};
std::cout << (wdi.ok()) << '\n';
}