Comment by pcfwik
2 days ago
Since this is about C declarations: for anyone who (like me) had the misfortune of learning the so-called "spiral rule" in college rather than being taught how declarations in C work, below are some links that explain the "declaration follows use" idea that (AFAIK) is the true philosophy behind C declaration syntax (and significantly easier to remember/read/write).
TL;DR: you declare a variable in C _in exactly the same way you would use it:_ if you know how to use a variable, then you know how to read and write a declaration for it.
https://eigenstate.org/notes/c-decl https://news.ycombinator.com/item?id=12775966
if you know how to use a variable, then you know how to read and write a declaration for it.
In other words, the precedence of operators in a declaration have exactly the same precedence as in its use.
That is correct.
Using x, or dereferencing p, or subscripting the array arr, or declaring a function that can be called with fn, or dereferencing the function pointer pfn then calling it, all these things would produce an int.
It's the intended way to read/write declarations/expressions. As a consequence, asterisks ends up placed near the identifiers. The confused ones will think it's a stylistic choice and won't understand any of this.
Blame Stroustrup.
https://www.stroustrup.com/bs_faq2.html#whitespace
Of course, the correct way to use a function pointer is to call it.
Yes, the () operator dereference function pointers automatically for you for convenience. There's also the surprise that you can infinitely dereference function pointers as they just yield you more function pointers.
2 replies →
> It's the intended way to read/write declarations/expressions. As a consequence, asterisks ends up placed near the identifiers.
You know you don't always have to use things as they were intended?
> The confused ones will think it's a stylistic choice and won't understand any of this.
Well, I've written it both ways, and the compiler never seems to mind. :)
Maybe I should start putting space on both sides of the asterisk; seems like it would be a good way to annoy even more people.