std::chrono::month_day::ok
From cppreference.com
 
 
 
 
 
 C++ 
 Feature test macros (C++20)
 Concepts library (C++20)
 Metaprogramming library (C++11)
 Ranges library (C++20)
 Filesystem library (C++17)
 Concurrency support library (C++11)
 Execution control library (C++26)
Date and time library 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(C++11)
(C++20)
  (C++20)
(C++11)
(C++11)
(C++11)
(C++20)
(C++20)
(C++20)
(C++11)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
  (C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
std::chrono::month_day 
 
 
 Member functions
month_day::ok
 Nonmember functions
 Helper classes
(C++26)
constexpr bool ok() const noexcept;
 
 (since C++20) 
Determines whether this month_day stores a valid month-day combination.
The combination is valid if month() represents a valid month (month().ok() == true), unsigned{day()} >= 1, and unsigned{day()} <= D, where D is the number of days in the month represented by month(). The number of days in February is considered to be 29.
[edit] Return value
true if the month and day combination is valid, otherwise false.
[edit] Example
Run this code
#include <chrono> #include <iostream> int main() { std::cout << std::boolalpha ; constexpr auto md1{std::chrono::July /15}; std::cout << (md1.ok()) << ' '; constexpr std::chrono::month_day md2{std::chrono::month (14), std::chrono::day (42)}; std::cout << (md2.ok()) << ' '; constexpr auto md3{std::chrono::February /29}; std::cout << (md3.ok()) << '\n'; }
Output:
true false true