std::chrono::year_month_weekday_last::ok

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chrono I/O
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C-style date and time
constexpr bool ok( ) const noexcept ;
(since C++20)

Checks if this object represents a valid date. Since a year_month_weekday_last represents the last weekday of a particular month, it is valid as long as the year, month and weekday are valid.

Return value

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

Example

#include <cassert>
#include <chrono>
using namespace std::chrono;
 
int main()
{
    auto ymwdl{Tuesday[last]/11/2020};
    assert(ymwdl.ok());
    ymwdl = Tuesday[last]/-2/2021;
    assert(!ymwdl.ok());
    ymwdl += months(0); // Normalize month
    assert(ymwdl.ok());
}