Checking If a Function Pointer is Valid

Question:
I am collecting a number of function pointers in C++ and before I call them I want to check to see if they have been set. I really want to avoid calling them if they aren’t valid. I have triedthe following “if func != Null { … ” but I get an error.

Answer:
First of all, there’s no ‘Null’ in C++. The constant NULL is all uppercase. However, it’s not a keyword so you have to #include a header file to make its definition visible to the compiler. The best way check for nullness is to compare the pointer (any type of pointer, including a pointer to member) to the literal zero:

if (pmf!=0)

Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

iOS app development

The Future of iOS App Development: Trends to Watch

When it launched in 2008, the Apple App Store only had 500 apps available. By the first quarter of 2022, the store had about 2.18 million iOS-exclusive apps. Average monthly app releases for the platform reached 34,000 in the first half of 2022, indicating rapid growth in iOS app development.

microsoft careers

Top Careers at Microsoft

Microsoft has gained its position as one of the top companies in the world, and Microsoft careers are flourishing. This multinational company is efficiently developing popular software and computers with other consumer electronics. It is a dream come true for so many people to acquire a high paid, high-prestige job

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a