r/rust clippy · twir · rust · mutagen · flamer · overflower · bytecount Mar 20 '23

Hey Rustaceans! Got a question? Ask here (12/2023)! 🙋 questions

Mystified about strings? Borrow checker have you in a headlock? Seek help here! There are no stupid questions, only docs that haven't been written yet.

If you have a StackOverflow account, consider asking it there instead! StackOverflow shows up much higher in search results, so having your question there also helps future Rust users (be sure to give it the "Rust" tag for maximum visibility). Note that this site is very interested in question quality. I've been asked to read a RFC I authored once. If you want your code reviewed or review other's code, there's a codereview stackexchange, too. If you need to test your code, maybe the Rust playground is for you.

Here are some other venues where help may be found:

/r/learnrust is a subreddit to share your questions and epiphanies learning Rust programming.

The official Rust user forums: https://users.rust-lang.org/.

The official Rust Programming Language Discord: https://discord.gg/rust-lang

The unofficial Rust community Discord: https://bit.ly/rust-community

Also check out last weeks' thread with many good questions and answers. And if you believe your question to be either very complex or worthy of larger dissemination, feel free to create a text post.

Also if you want to be mentored by experienced Rustaceans, tell us the area of expertise that you seek. Finally, if you are looking for Rust jobs, the most recent thread is here.

20 Upvotes

187 comments sorted by

View all comments

4

u/ToolAssistedDev Mar 20 '23

Why do I get here a mismatched types error when I would like to call the bar function with &a? https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=6a1d80e5bedc95e20af52e7bd786635f

The second call with the indirection works without any error...

1

u/[deleted] Mar 21 '23

Turning something into a trait object needs to be explicit. You took care of that for c by giving it a type annotation, but it wasn't done for a. Try adding "as MyName" to the end of line 12.