How to read complicated Rust types

I'm speechless. This was so incredibly helpful! Exactly what I was looking for and more. It's crazy how much info there is to unpack in that one example. Rust is so strict and descriptive, while not being overly verbose --- one of the reasons I'm loving this language. Anyway, really appreciate seeing your thought process as you tackle a complicated function like this and your ad-lib-ish teaching style! Looking forward to more vids

This is some brainy shit. To be honest, I think many Rust programmers take this stuff way too far. Crazy levels of generic abstraction, but when I get the stopwatch out it factors slower than a naive implementation, which may not have been blessed with the same levels of abstraction, but is easily understood and manipulated. Still, thank you for analyzing, and getting to the bottom of things!

Nice. It is also important to note that this `recover` method consumes its object, `self`.

What window manager are you using?

I love your videos. I wondered how best to create a pool of Reqwest clients and map them to Axum as "with_state".

I greatly value this video for its immense usefulness, as it provides a wealth of valuable insights and information. Your generosity in sharing such valuable knowledge is deeply appreciated, and it demonstrates your commitment to empowering others through education and enlightenment.

Headache, this is all I can feel rn

Story of my life. I don't handle rejection very well and I always get into generic arguments with people.

The quick answer I would give for this case, is that it is a method on a trait that returns a type which has the same name as the function but in uppercase.

In those cases, the very first thing I would check is whether the returned type satisfies the trait it is defined on, in this case whether it returns a filter. In those cases, the idea is generally that you do not care what specific filter you have, you just care that you have an object satisfying that interface, and filter is a method that takes a filter and return a filter, possibly modifying it/adding middleware in some way.

So it should be read like this?
Self should implement Filter (with Error, where Error is Rejection) and Sized
F should implement Func (with Rejection)
F's associated type Output should implement TryFutere and Send
F's associated type Output for type TryFutere and this TryFutere's associated type Error should implement IsReject

Amazing channel and video, but Rust still too hard to read and fully understand. I still prefer my elixir for doing WebAPI and use rust to complement when needed it.

Love it!
Speaking of breaking things down, I'd love for you to do a video on "how to grok the rust docs"! Half the time, I give up when I cant effectively look things up in the docs. I feel like it has its own grammar so to speak.

Thanks for this. The associated type thing helped me a lot! <3

Amazing videos. I am glad you are getting so many views.

Rust looks like overcomplicated languages. So why do we need it?

tip with your subtitles: try and keep them the same length-ish, usually a single or half of a sentence

the only confusing part is the where, yet the rust where restriction is powerful and typescript like

You catch on really fast, it seems complex but once you learn the basics it pretty much branches into experintation

Hi Chris, I'm very thankful for the subtitles. Could you make them a bit more split please? The wall of text sometimes hides the video and it can be hard to focus to read all in once. Thank you in advance!

you know that by now tho

thanks, Chris! How did you got so good at 'reading' Rust :D

Hey Chris nice video!
Do you know where can I find architecture books for Rust?

Sized is a marker trait, it is basically used to mark a type and say it can't be dynamic, which means that you can't have a Vec<dyn Filter> because Filter must be sized.

I like almost any content you create for us

gonna be real this did not help me at all, assumes way too much knowledge

"Handle rejection is gonna be that F" yep

How to read rust docs

I'm actually very surprized how intuitive this function looks. If you just know the consept of traits and at least heard of associated types, then this code means exactly what it's looks like:

Self: has to implement filter trait, associatied type Error of witch has to be Rejection, and it also has to implement Func;
F: has to implement Func with generic arg Rejection
F::Output (associated type of Func, since we already specified that F implements Func) has to implement traits TryFuture + Send,
F::Output::Error (associated type of TryFuture, as we manualy speccified) has to implement IsReject.



The only two things that are not really clear for me:
1) Why we HAVE TO speccify F::Output as TryFuture to set constraint to Error, but don't have to specify F as Func to set constraint to Output? I thought that this is because Output constrained to implement 2 traits (TryFuture + Send), but if i remove Send, it still won't compile unless I manualy speccify Output as TryFuture...

2) Why I get an error if I remove Sized constraint from Self? I thought that the type of Self already has to be known at compile time => size also has to be known.
Actually, I found answer to the second question: it's because trait object exist (dyn &MyTrait), so theoreticly Self can be not known at compile time. Still, a bit confusing...

This is just jibberish. 😅

I wish people would write full names for generic type variable instead of using a single capital letter.

Feels so boring, to read and understand that code

Excellent walkthrough, thank you!

Great video! Thank you 🙏🏾

thx

Thank You For TeacNice tutorialng Us Brother

Very well explained, thanks a lot!

Super helpful video !

Good content. Very informative and worth a sub. I found this via the homepage. Ive been consuming some rust related content lately. Never used the language yet and Ive been put off by many cases like this. As a personal background I am a hobbyist developer with primarily java experience.

Hello there, God bless your efforts.
I am a new sql learner having a general enquiry.
How a company manages to write a documentation of its own sql application?
I would be so grateful for any kind of help.

YOU ARE AMAZING! Your channel is so underrated. Every video that you create is always approachable and easy to follow, even without understanding everything. Thanks so much for everything that you do <3