std::chrono::month_weekday:: ok

检查所包含的 month 和 weekday_indexed 对象是否有效。

返回值

month ( ) . ok ( ) && weekday_indexed ( ) . ok ( )

示例

#include <cassert>
#include <chrono>
int main()
{
    auto mwdi{std::chrono::March/std::chrono::Friday[1]};
    assert(mwdi.ok());
    mwdi = {std::chrono::month(17)/std::chrono::Friday[1]}; 
    assert(not mwdi.ok());
    mwdi = {std::chrono::March/std::chrono::Friday[-4]}; 
    assert(not mwdi.ok());
}