'static'是否为c ++类成员函数？

Question

Why is the static keyword necessary at all?

Why can't the compiler infer whether it's 'static' or not?

As follows:

Can I compile this function without access to non-static member data? Yes -> static funcion. No -> non-static function.

Is there any reason this isn't inferred?

Answer 1

如果您希望编译器在现场决定它是否是静态的，那么它如何影响链接到仅定义方法签名的头文件的外部源文件？

Answer 2

The propery of being static or non-static affects the function type. Non-static member functions have an implicit this parameter, while static ones don't, for one example.

In other words, there's a major qualitative difference between static and non-static member functions. The compiler cannot "infer" this. This is a matter of the author's intent.

If I want (and need) my function to be non-static, I make it non-static, even if it doesn't access any non-static members of the class. If the compiler suddently decides to make my non-static function static just because it doesn't access any non-static members of the class, in general case it will destroy the functionality of the code.

Answer 3

Yes the compiler could, but it has no knowledge of your intent. And the original designers probably thought that supplying your intent was important.

Answer 4

在语言中具有这样的冗余有助于确保许多程序员错误最终会被编译器捕获。

Answer 5

Another reason: If the function is static, it can't be overridden in derived classes. No polymorphism.