apress/beginning-cpp20

Source Code for 'Beginning C++20' by Ivor Horton and Peter Van Weert

Apress Source Code

This repository accompanies Beginning C++20 by Ivor Horton and Peter Van Weert (Apress, 2020).

Download the files as a zip using the green button, or clone the repository to your machine using Git. To make sure you also clone the 3rd party submodules in the Workarounds directory, we recommend using the following Git command:

git clone --recursive https://github.com/Apress/beginning-cpp20.git

C++20 Compiler Support

At the time the book was completed, not a single compiler supported all C++20 features yet. We recommend you consult the Workarounds section on how to work around any compilation issues you may experience.

Contributions

See the file Contributing.md for more information on how you can contribute to this repository.

beginning-cpp20's Issues

#include <format>

1. env:

gcc --version
gcc (GCC) 11.3.1 20221121 (Red Hat 11.3.1-4)
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


g++ --version
Apple clang version 14.0.0 (clang-1400.0.29.202)
Target: arm64-apple-darwin22.1.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

2. error:

cd "/root/ws/beginning-cpp20/Examples/NoModules/Chapter 02/" && g++ -std=c++20 Ex2_03B.cpp -o Ex2_03B.exe && "/root/ws/beginning-cpp20/Examples/NoModules/Chapter 02/"Ex2_03B.exe
Ex2_03B.cpp:3:10: fatal error: format: No such file or directory
    3 | #include <format>
      |          ^~~~~~~~
compilation terminated.

3. cppreference

cppreference

4. my opinion

It's like a joke

Does the chapter 13 page 495 definning postfix operator++ wrong?

I'm sorry to bother you, but I found a problem here. in the page 495, we define a postfix operator++.

But when I run the code, the compiler warned that the variable copy is a local variable, which caused segementation fault.

emm, I tried to change the copy to static and it worked. But you know, only once.

So, how can I define a right version of the operator?

Which compiler you use to run the examples ?

I can't find easily a compiler that support import statements as in the first example in the book.
Do you recommend a specific compiler to install ?

Exercise 2-4 code wrong?

For the exercise 2-4 answer, a person's height in meters is calculated as this:

h_meters { meters_per_foot * h_feet + h_inches / inches_per_foot };

This converts the recorded feet to meters, but then converts the recorded inches to feet and adds feet to meters, which doesn't make sense. I believe this leads to incorrect BMI values.

It should be this:

h_meters { meters_per_foot * (h_feet + h_inches / inches_per_foot) };

std::format is not implemented

None of the major vendors implements the format header yet. Hence, none of the book examples that use them work at the moment. There is a workaround by using fmt library, however requires extra work. Please update the appendix and provide clear instructions to install the fmt library to make the examples work. Or replace the std::format examples with stream formatting.

No offense, but has anyone tried to compile the source code? This is a minimum effort required to do when writing a book aimed at "beginners".

Is there a reason why Chapter 7's s module examples and exercises are missing from this repo?

Chapter 7 has No Modules examples and exercises, converting the non-module examples/exercises is a good exercise for reinforcing one's knowledge of C++20, but it is a bit strange to have an entire chapter's source code using modules not available.

book errata - ASCII Codes

Where can errata get submitted for the book?

page 21 - ASCII Codes

lowercase letters have the sixth bit as 0, and uppercase letters have the sixth bit as 1

This should be

lowercase letters have the sixth bit as 1, and uppercase letters have the sixth bit as 0