Explaining Pointers Until I Go Insane

Hello there! I've been wanting to talk about quirky pointers for a while. They make no sense sometimes.

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[MultsElMesco]

Hello everyone! I've been doing some mix and match with my content style lately. Just trying new things. Let me know what you think :)

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[tuhkiscgibin]

If a codebase has any of this stuff, you'll know it's been backdoored.

[vulnoryx]

"say pointer again"
"fuck you"

[eleinaedelweiss]

Who the hell would write the last one, without questioning their lives decisions.

[Suspaghetti]

You realize how complicated pointer syntax is when the best explanation of how to read complex statements is in a funny YT video

[Hallilo]

I honestly never had any issues understanding basic and more advanced pointer stuff, but THIS is some actual good stuff LMAO great video

[Spitfire]

Aight I'm never listening to the word "pointer" again

[ry]

Honestly,
An array of functions sounds pretty dope.

Nevermind, an array of pointers to functions sounds pretty dope.

[dipereira]

to whoever reached a point in life where you ended up here or doing this, i really hope you find inner peace one day...

[moneteezee]

im actually glad i found this video, you explained this well and now i know how to interpret those long lines

[JoaoJGabriel]

It all can get stupidly complicated as we've seen, but the syntax follows simple rules:

1. start reading from the identifier out
2. favor [ ] and ( ) over *

int (*(*x)[ ]) ( ):

- Following rule #1, we start at x
x
- The identifier x is alone in parentheses with an asterisk, so it is [§1] a pointer
*x
- Outside of the parentheses, we follow rule #2, so it is [§2] an array
(*x)[ ]
- We're left with an asterisk inside the parentheses, so [§3] pointers
*(*x)[ ]
- Outside of the parentheses, rule #2, [§4] functions
(*(*x)[ ])( )
- The functions return [§5] int
putting §1, §2, §3, §4 and §5 together:
x is (§1) a pointer to (§2) an array of (§3) pointers to (§4) functions that return (§5) an integer

Once you got the hang of it, you can rewrite the example like:
* [ ] * ( ) -> int
And stitch things together in a way that makes sense. "->" means "returns" and it's optional/redundant (anything immediately after parentheses in this notation is a return anyway)

Take the example of 5:34:
[ ] * * (* char, * (* char) -> * int) -> [ ] * (* * char, * ( ) -> * char) -> * int
Array of pointers to a pointer to a function that takes (a pointer to a character and a pointer to a function that takes (a pointer to a character) and returns a pointer to an integer) and returns an array of pointers to a function that takes (a pointer to a pointer to a character and a pointer to a function that returns a pointer to a character) and returns a pointer to an integer

It looks insane, but it's not that difficult to wrap your head around if you're writing it following those two simple rules

[NicolasChanCSY]

A programmer goes to therapy.
Therapist: Please tell me what you are scared of.
Programmer: I am scared of pointers.
Therapist: Okay, let me give you an array of pointers to handle them.
Programmer: 😱😱😱

[BaneDestabapillado]

Small tip for 1:20, you can order malloc like you did just by manually asking for each memory "sizeof(char) * 6..." but if you make a tipedef of your struct, you can just ask for a "sizeof(FUCKER)" and it will do the same, but far easier to read, and simpler

[James-netd]

"For example, if I use this struct 'Fucker'" caught me completely off guard XD

My main takeaway from this video though is that as a C# dev for Unity, I shouldn't touch C++ with a 5 foot pole or else risk entering pointer hell.

[no-ldhz]

3:24 funnily enough this is how dynamic dispatch works in c++, each class (implicitly) creates a pointer to a global array of function pointers. This is also known as a virtual table or vtable/vftable as it contains the list of "virtual" functions for that class.

[tvardero]

6:00 Bro is holding the entire class inside his variable definition

The God Variable.

[marcsfeh]

C's syntax makes things excessively hard to parse, in other languages like C3 or more Pascal style languages (like Go and Odin) it's much more clear how these declarations compose

[jatinsharma]

Man, It felt awesome and confusing at the same time, but thanks to you I come to know the different use of pointers.

[halflight]

this is what I understood from 3:10


- arr[0] -> func1 => int1
- arr [1] -> func2 => int2
x ->arr - arr[2] -> func3 => int3
- arr[3] -> func4 => int4
- arr[4] -> func5 => int5

[norude]

I think, most of the confusion comes from the syntax.

For example, int (*(*x)[])()
in Rust, would be Box<Vec<Box<Fn() -> i32>>>

"Box" is Rust's pointer
i32 is Rust's int