到底怎麼寫inline才是對的...https://www.geeksforgeeks.org/inline-functions-cpp/The best programming style is to just write the prototype of function inside the class and specify it asan inline in the function definition.範例這反而沒看過這樣寫...而且這樣寫,.so要怎麼讓外部連結的人在compile time做inline