Forward declaration is a way to tell the compiler "hey, this thing exists, I promise" without actually defining it yet. It's like when your friend says they'll buy you a drink later, but you both know they're probably lying and will conveniently "forget" their wallet.

How to use it in a sentence

• I tried to use the Foo class in my code, but apparently I need to add a forward declaration first. Guess I'll just add it to the ever-growing list of things to do before this project can even compile.

• Bob: "Why is the build failing?" Alice: "Oh, it's just a missing forward declaration. I'll add it in a few days when I feel like dealing with this legacy codebase again."

If you actually want to learn more...

• C++ Forward Declaration: GeeksforGeeks provides a straightforward explanation of forward declaration in C++, including when and why you might want to use it. Read more

• Forward Declarations in C++: Educative dives into the details of forward declaration in C++, explaining how it allows you to use a type before it's fully defined. Perfect for when you want to impress your coworkers with your obscure C++ knowledge. Read more

• Forward Declaration in C: Tech Crash Course covers forward declaration in C, because apparently some people still write C code in 2023. But hey, if you're into that sort of thing, this article is for you. Read more

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