Red

Rust Brain Teasers: Doubling the right value (page 69?)

The page number is absent for the “card” pages unfortunately, but it’s before page 70.

println!("2 * 4 = {}", double_it(2));

should be

println!("2 * 4 = {}", double_it(4));

It won’t change the outcome, but I’d put a “4” at least just for the sake of clarity.

5 comments

#errata /book-rust-brain-teasers

0 579 5

2022-08-05 14:10:32 UTC

First Post!

Red

I must admit that missing features like overloading and default parameters requires some boilerplate code sometimes, it’s sad. Hopefully they’ll get around to providing that in a distant future but it seems to require a tremendous amount of discussion before reaching any decision.

In comparison, Kotlin has its development started slightly later by a small team (at Jetbrains) and is now much more flexible. It also includes more libraries, for which Rust must rely on external crates (and are for the most part yet in beta stage…).

Those are the little drawbacks of this otherwise awesome language.

Post #2

Where Next?

View thread on forum

View Rust Brain Teasers's book portal

Post errata for this book

Post a suggestion for this book

Post a question about this book

Post a review about this book

Home PragProg Customers

#errata /book-rust-brain-teasers

0 579 5

Last post

Popular Pragmatic Bookshelf topics

PragProg Customers

Distributed Services With Go - Ch 3 index errors on Config

In Chapter 3, the source for index introduces Config on page 31, followed by more code including tests; Config isn’t introduced until pag...

#pragprog #errata /book-distributed-services-with-go

8 1316 3

2021-04-08 12:48:40 UTC

New

PragProg Customers

Apple Game Frameworks and Technologies: Screen image may be wrong (p 13)

Working through the steps (checking that the Info,plist matches exactly), run the demo game and what appears is grey but does not fill th...

#errata /book-apple-game-frameworks-and-technologies

11 1081 5

2021-05-15 17:31:07 UTC

New

PragProg Customers

Programming Machine Learning: Incorrect formula

Hi everyone! There is an error on the page 71 in the book “Programming machine learning from coding to depp learning” P. Perrotta. You c...

#errata /book-programming-machine-learning

5 1341 4

2022-04-06 12:03:54 UTC

New

PragProg Customers

Modern CSS with Tailwind: can’t setup the Rails source code

I can’t setup the Rails source code. This happens in a working directory containing multiple (postgres) Rails apps. With: ruby-3.0.0 s...

#question /book-modern-css-with-tailwind

0 1280 3

2021-03-27 15:29:34 UTC

New

PragProg Customers

Modern Front-End Development for Rails: Can't get TURBO_STREAM format in some cases

This isn’t directly about the book contents so maybe not the right forum…but in some of the code apps (e.g. turbo/06) it sends a TURBO_ST...

#question /book-modern-front-end-development-for-rails

1 1386 7

2021-04-04 21:22:11 UTC

New

PragProg Customers

Kotlin and Android Development featuring Jetpack: SwitchCompat's thumbTint and trackTint being ignored (page 76)

I think I might have found a problem involving SwitchCompat, thumbTint, and trackTint. As entered, the SwitchCompat changes color to hol...

#errata /book-kotlin-and-android-development-featuring-jetpack

0 2749 2

2022-05-13 11:00:18 UTC

New

PragProg Customers

Python Testing with pytest, Second Edition: unrecognized arguments error (page 122)

When I run the coverage example to report on missing lines, I get: pytest --cov=cards --report=term-missing ch7 ERROR: usage: pytest [op...

#errata /book-python-testing-with-pytest-second-edition

0 4000 1

2021-12-03 05:36:38 UTC

New

PragProg Customers

Agile Web Development with Rails 7: page 113 - Seeing the list of products

I’m a newbie to Rails 7 and have hit an issue with the bin/Dev script mentioned on pages 112-113. Iteration A1 - Seeing the list of prod...

#question /book-agile-web-development-with-rails-7

0 2631 9

2024-01-06 20:36:27 UTC

New

PragProg Customers

PragProg Customers Kotlin and Android Development: pg. 8 Build Gradle error: Could not get unknown property 'kotlin_version'

I am using Android Studio Chipmunk | 2021.2.1 Patch 2 Build #AI-212.5712.43.2112.8815526, built on July 10, 2022 Runtime version: 11.0....

#question /book-kotlin-and-android-development-featuring-jetpack

0 1456 2

2022-08-29 14:30:50 UTC

New

PragProg Customers

Programming Machine Learning: some plot files are throwing error

I got this error when executing the plot files on macOS Ventura 13.0.1 with Python 3.10.8 and matplotlib 3.6.1: programming_ML/code/03_...

#question /book-programming-machine-learning

1 3055 5

2023-09-17 09:42:29 UTC

New

Other popular topics

Backend>Learning Resources

Seven Languages in Seven Weeks

Ruby, Io, Prolog, Scala, Erlang, Clojure, Haskell. With Seven Languages in Seven Weeks, by Bruce A. Tate, you’ll go beyond the syntax—and...

pragprog.com

#pragprog /clojure /erlang /haskell /prolog /ruby /scala #published-book /book-seven-languages-in-seven-weeks

5 5730 1

2022-01-20 13:48:55 UTC

New

General Dev>Hardware

What monitor(s) do you have for programming?

Please tell us what is your preferred monitor setup for programming(not gaming) and why you have chosen it. Does your monitor have eye p...

#monitors #coding #programming #development

227 11362 88

2022-02-01 12:02:08 UTC

New

General Dev>Dev Chat

Standing Desks

No chair. I have a standing desk. This post was split into a dedicated thread from our thread about chairs :slight_smile:

#workspace #opinions

177 9886 77

2022-09-27 18:40:05 UTC

New

Backend>Chat

Using Regular Expressions in Erlang

Intensively researching Erlang books and additional resources on it, I have found that the topic of using Regular Expressions is either c...

/erlang #regular-expressions

91 5662 43

2021-09-06 19:12:48 UTC

New

Data Science

Can AI/ML predict a lottery win?

Biggest jackpot ever apparently! :upside_down_face: I don’t (usually) gamble/play the lottery, but working on a program to predict the...

#ai #machine-learning

19 3939 10

2021-10-18 19:01:41 UTC

New

Community>In The Spotlight

Spotlight: Mike Riley (Author) Interview and AMA!

Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...

#author-spotlight /python #iot /book-portable-python-projects #internet-of-things

62 7035 19

2022-06-09 14:01:01 UTC

New

Community>In The Spotlight

Spotlight: VM Brasseur (Author) Interview and AMA!

Author Spotlight: VM Brasseur @vmbrasseur We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...

#author-spotlight /book-forge-your-future-with-open-source

16 5051 11

2023-03-27 16:00:12 UTC

New

Game Dev>Questions

I want to learn how make a game, but where should I start?

I’m able to do the “artistic” part of game-development; character designing/modeling, music, environment modeling, etc. However, I don’t...

#game-dev

15 4965 9

2025-10-18 13:12:58 UTC

New

Backend>Learning Resources

Ash Framework

Explore the power of Ash Framework by modeling and building the domain for a real-world web application. Rebecca Le @sevenseacat and ...

pragprog.com

#pragprog /elixir #published-book /ash /book-ash-framework

15 7555 9

2025-02-06 12:19:21 UTC

New

AI>Chat

Post your DeepSeek results

Curious what kind of results others are getting, I think actually prefer the 7B model to the 32B model, not only is it faster but the qua...

/deepseek

15 4275 15

2025-03-06 23:29:12 UTC

New

Rust Brain Teasers: Doubling the right value (page 69?)

Red

Rust Brain Teasers: Doubling the right value (page 69?)

First Post!

Red

Where Next?

Popular Pragmatic Bookshelf topics

Distributed Services With Go - Ch 3 index errors on Config

Apple Game Frameworks and Technologies: Screen image may be wrong (p 13)

Programming Machine Learning: Incorrect formula

Modern CSS with Tailwind: can’t setup the Rails source code

Modern Front-End Development for Rails: Can't get TURBO_STREAM format in some cases

Kotlin and Android Development featuring Jetpack: SwitchCompat's thumbTint and trackTint being ignored (page 76)

Python Testing with pytest, Second Edition: unrecognized arguments error (page 122)

Agile Web Development with Rails 7: page 113 - Seeing the list of products

PragProg Customers Kotlin and Android Development: pg. 8 Build Gradle error: Could not get unknown property 'kotlin_version'

Programming Machine Learning: some plot files are throwing error