by yituan @yi-tuan
Implement the advanced util type OptionalKeys<T>, which picks all the optional keys into a union.
-5%E3%83%BB%E8%8E%B7%E5%8F%96%E5%8F%AA%E8%AF%BB%E5%AD%97%E6%AE%B5-b11b8d" alt="5・获取只读字段"/>
by yituan @yi-tuan
Implement the advanced util type OptionalKeys<T>, which picks all the optional keys into a union.
-5%E3%83%BB%E8%8E%B7%E5%8F%96%E5%8F%AA%E8%AF%BB%E5%AD%97%E6%AE%B5-b11b8d" alt="5・获取只读字段"/>