函数指针成员函数 [英] function pointers member functions

问题描述

您好，

我正在处理类成员函数的函数指针

并且它们被设置为回调等。

然后，被调用。

我的问题是我认为检查函数

指针是否已设置为NULL等是个好主意？对吗？

例如，可能在调用它们之前等等。??



谢谢。

Hello,
I am dealing with function pointers to classes member functions
and they are being set as callbacks etc.
Then, been invoked.
My question is I think it is a good idea to check the function
pointers whether they have been set to NULL etc.? right?
e.g., maybe before invoking them etc.??

Thanks.

推荐答案

在提出问题之前做一些研究总是一个好主意。在过去的几天里有几个关于成员函数指针的问题，这些答案中的任何一个都对你有价值。



关于指针零点检查：下面的句子是如此微不足道，以至于我几乎不敢把它作为一个建议：它从不伤害检查，但​​也绝不保证指针有效。您应该通过其他方式（正确初始化）确保您的指针（数据指针或成员函数指针等）具有有效值。



当然，您可以使用零值表示成员函数指针当时无效，例如因为到目前为止还没有指定回调。

It is always a good idea to do some research before asking a question. There were a couple of questions about member functions pointers in last few days and any of those answers would have been valuable for you.

Regarding a Zero check on pointers: The following sentence is so trivial that I am almost afraid to give that as an advice: It never hurts to check, but is also never a guarantee that a pointer is valid otherwise. You should make sure by other means (correct initialization) that your pointers (data pointer or member function pointers alike) have a valid value.

Of course, you can use the zero-value is indication that the member function pointer is not valid at the time, for example because no callback has been specified so far.

在你之前检查总是一个好主意调用一个电话。



你可以插入断言来检查调试时间以确保函数不为空

It is always a good idea to check before you invoke a call.

You can insert assert to check on debug time to make sure that function is not empty

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