std::chrono::year_month_day_last::ok

From cppreference.com
 
 
Utilities library
General utilities
Relational operators (deprecated in C++20)
 
 
 
constexpr bool ok() const noexcept;
(since C++20)

Checks if *this represents a valid date. Because a year_month_day_last represents the last day of a particular month, it represents a valid date as long as the year and month are valid.

Return value

year().ok() && month().ok()

Example

#include <cassert>
#include <chrono>
 
int main()
{
    auto ymdl{std::chrono::last/11/2020};
    assert(ymdl.ok());
    ymdl = std::chrono::year(2020)/std::chrono::month(13)/std::chrono::last;
    assert(not ymdl.ok());
}