std::chrono::year_month::ok (3) - Linux Manuals
std::chrono::year_month::ok: std::chrono::year_month::ok
NAME
std::chrono::year_month::ok - std::chrono::year_month::ok
Synopsis
constexpr bool ok() const noexcept; (since C++20)
Checks if the year and month values stored in this object are valid.
Return value
year().ok() && month().ok()