C++20 for Programmers: An Objects-Natural Approach

by Paul Deitel, Harvey Deitel

Overview

The professional programmer's Deitel^® guide to C++20

Written for programmers with a background in another high-level language, in this book, you'll learn Modern C++ development hands on using C++20 and its "Big Four" features—Ranges, Concepts, Modules and Coroutines. (For more details, see the Preface, and the table of contents diagram inside the front cover.)

In the context of 200+, hands-on, real-world code examples, you'll quickly master Modern C++ coding idioms using popular compilers—Visual C++^®, GNU^® g++, Apple^® Xcode^® and LLVM^®/Clang. After the C++ fundamentals quick start, you'll move on to C++ standard library containers array and vector; functional-style programming with C++20 Ranges and Views; strings, files and regular expressions; object-oriented programming with classes, inheritance, runtime polymorphism and static polymorphism; operator overloading, copy/move semantics, RAII and smart pointers; exceptions and a look forward to C++23 Contracts; standard library containers, iterators and algorithms; templates, C++20 Concepts and metaprogramming; C++20 Modules and large-scale development; and concurrency, parallelism, the C++17 and C++20 parallel standard library algorithms and C++20 Coroutines.

Features

• Rich coverage of C++20's "Big Four": Ranges, Concepts, Modules and Coroutines
• Objects-Natural Approach: Use standard libraries and open-source libraries to build significant applications with minimal code
• Hundreds of real-world, live-code examples
• Modern C++: C++20, 17, 14, 11 and a look to C++23
• Compilers: Visual C++^®, GNU^® g++, Apple Xcode^® Clang, LLVM^®/Clang
• Docker: GNU^® GCC, LLVM^®/Clang
• Fundamentals: Control statements, functions, strings, references, pointers, files, exceptions
• Object-oriented programming: Classes, objects, inheritance, runtime and static polymorphism, operator overloading, copy/move semantics, RAII, smart pointers
• Functional-style programming: C++20 Ranges and Views, lambda expressions
• Generic programming: Templates, C++20 Concepts and metaprogramming
• C++20 Modules: Large-Scale Development
• Concurrent programming: Concurrency, multithreading, parallel algorithms, C++20 Coroutines, coroutines support libraries, C++23 executors
• Future: A look forward to Contracts, range-based parallel algorithms, standard library coroutine support and more

"C++20 for Programmers builds up an intuition for modern C++ that every programmer should have in the current software engineering ecosystem. The unique and brilliant ordering in which the Deitels present the material jibes much more naturally with the demands of modern, production-grade programming environments. I strongly recommend this book for anyone who needs to get up to speed on C++, particularly in professional programming environments where the idioms and patterns of modern C++ can be indecipherable without the carefully crafted guidance that this book provides."
—Dr. Daisy Hollman, ISO C++ Standards Committee Member

"This is a fine book that covers a surprising amount of the very large language that is C++20. An in-depth treatment of C++ for a reader familiar with how things work in other programming languages."
—Arthur O'Dwyer, C++ trainer, Chair of CppCon's Back to Basics track, author of several accepted C++17/20/23 proposals and the book Mastering the C++17 STL

"Forget about callback functions, bare pointers and proprietary multithreading libraries—C++20 is about standard concurrency features, generic lambda expressions, metaprogramming, tighter type-safety and the long-awaited concepts, which are all demonstrated in this book. Functional programming is explained clearly with plenty of illustrative code listings. The excellent chapter, 'Parallel Algorithms and Concurrency: A High-Level View,' is a highlight of this book."
—Danny Kalev, Ph.D. and Certified System Analyst and Software Engineer, Former ISO C++ Standards Committee Member

Register your book for convenient access to downloads, updates, and/or corrections as they become available. See inside book for details. Note: eBooks are 4-color and print books are black and white.

Product Details

ISBN-13:	9780136905691
Publisher:	Pearson Education
Publication date:	04/16/2022
Series:	Deitel Developer Series
Edition description:	3rd ed.
Pages:	960
Product dimensions:	7.00(w) x 9.12(h) x 1.75(d)

About the Author

Paul Deitel, CEO and Chief Technical Officer of Deitel & Associates, Inc., is a graduate of MIT, where he studied Information Technology. He holds the Java Certified Programmer and Java Certified Developer designations, and is an Oracle Java Champion. Through Deitel & Associates, Inc., he has delivered hundreds of programming courses worldwide to clients, including Cisco, IBM, Siemens, Sun Microsystems, Dell, Fidelity, NASA at the Kennedy Space Center, the National Severe Storm Laboratory, White Sands Missile Range, Rogue Wave Software, Boeing, SunGard Higher Education, Nortel Networks, Puma, iRobot, Invensys and many more. He and his co-author, Dr. Harvey M. Deitel, are the world’s best-selling programming-language textbook/professional book/video authors.


Dr. Harvey Deitel, Chairman and Chief Strategy Officer of Deitel & Associates, Inc., has over 50 years of experience in the computer field. Dr. Deitel earned B.S. and M.S. degrees in Electrical Engineering from MIT and a Ph.D. in Mathematics from Boston University. He has extensive college teaching experience, including earning tenure and serving as the Chairman of the Computer Science Department at Boston College before founding Deitel & Associates, Inc., in 1991 with his son, Paul. The Deitels’ publications have earned international recognition, with translations published in Japanese, German, Russian, Spanish, French, Polish, Italian, Simplified Chinese, Traditional Chinese, Korean, Portuguese, Greek, Urdu and Turkish. Dr. Deitel has delivered hundreds of programming courses to corporate, academic, government and military clients.

Table of Contents

Preface xxi
Before You Begin xliii

Chapter 1: Intro and Test-Driving Popular, Free C++ Compilers 1
1.1 Introduction 2
1.2 Test-Driving a C++20 Application 4
1.3 Moore's Law, Multi-Core Processors and Concurrent Programming 16
1.4 A Brief Refresher on Object Orientation 17
1.5 Wrap-Up 20

Chapter 2: Intro to C++20 Programming 21
2.1 Introduction 22
2.2 First Program in C++: Displaying a Line of Text 22
2.3 Modifying Our First C++ Program 25
2.4 Another C++ Program: Adding Integers 26
2.5 Arithmetic 30
2.6 Decision Making: Equality and Relational Operators 31
2.7 Objects Natural: Creating and Using Objects of Standard-Library Class string 35
2.8 Wrap-Up 38

Chapter 3: Control Statements: Part 1 39
3.1 Introduction 40
3.2 Control Structures 40
3.3 if Single-Selection Statement 43
3.4 if…else Double-Selection Statement 44
3.5 while Iteration Statement 47
3.6 Counter-Controlled Iteration 48
3.7 Sentinel-Controlled Iteration 50
3.8 Nested Control Statements 54
3.9 Compound Assignment Operators 57
3.10 Increment and Decrement Operators 58
3.11 Fundamental Types Are Not Portable 60
3.12 Objects-Natural Case Study: Arbitrary-Sized Integers 61
3.13 C++20: Text Formatting with Function format 65
3.14 Wrap-Up 67

Chapter 4: Control Statements: Part 2 69
4.1 Introduction 70
4.2 Essentials of Counter-Controlled Iteration 70
4.3 for Iteration Statement 71
4.4 Examples Using the for Statement 74
4.5 Application: Summing Even Integers 74
4.6 Application: Compound-Interest Calculations 75
4.7 do…while Iteration Statement 78
4.8 switch Multiple-Selection Statement 80
4.9 C++17 Selection Statements with Initializers 85
4.10 break and continue Statements 86
4.11 Logical Operators 88
4.12 Confusing the Equality (==) and Assignment (=) Operators 92
4.13 Objects-Natural Case Study: Using the miniz-cpp Library to Write and Read ZIP files 94
4.14 C++20 Text Formatting with Field Widths and Precisions 98
4.15 Wrap-Up 100

Chapter 5: Functions and an Intro to Function Templates 101
5.1 Introduction 102
5.2 C++ Program Components 103
5.3 Math Library Functions 103
5.4 Function Definitions and Function Prototypes 105
5.5 Order of Evaluation of a Function's Arguments 108
5.6 Function-Prototype and Argument-Coercion Notes 108
5.7 C++ Standard Library Headers 111
5.8 Case Study: Random-Number Generation 113
5.9 Case Study: Game of Chance; Introducing Scoped enums 119
5.10 Scope Rules 124
5.11 Inline Functions 128
5.12 References and Reference Parameters 129
5.13 Default Arguments 132
5.14 Unary Scope Resolution Operator 133
5.15 Function Overloading 134
5.16 Function Templates 137
5.17 Recursion 139
5.18 Example Using Recursion: Fibonacci Series 142
5.19 Recursion vs. Iteration 145
5.20 Lnfylun Lhqtomh Wjtz Qarcv: Qjwazkrplm xzz Xndmwwqhlz 147
5.21 Wrap-Up 150

Chapter 6: arrays, vectors, Ranges and Functional-Style Programming 153
6.1 Introduction 154
6.2 arrays 155
6.3 Declaring arrays 155
6.4 Initializing array Elements in a Loop 155
6.5 Initializing an array with an Initializer List 158
6.6 C++11 Range-Based for and C++20 Range-Based for with Initializer 159
6.7 Calculating array Element Values and an Intro to constexpr 161
6.8 Totaling array Elements 163
6.9 Using a Primitive Bar Chart to Display array Data Graphically 164
6.10 Using array Elements as Counters 165
6.11 Using arrays to Summarize Survey Results 166
6.12 Sorting and Searching arrays 168
6.13 Multidimensional arrays 170
6.14 Intro to Functional-Style Programming 174
6.15 Objects-Natural Case Study: C++ Standard Library Class Template vector 180
6.16 Wrap-Up 187

Chapter 7: (Downplaying) Pointers in Modern C++ 189
7.1 Introduction 190
7.2 Pointer Variable Declarations and Initialization 192
7.3 Pointer Operators 192
7.4 Pass-by-Reference with Pointers 195
7.5 Built-In Arrays 199
7.6 Using C++20 to_array to Convert a Built-In Array to a std::array 201
7.7 Using const with Pointers and the Data Pointed To 202
7.8 sizeof Operator 205
7.9 Pointer Expressions and Pointer Arithmetic 208
7.10 Objects-Natural Case Study: C++20 spans—Views of Contiguous Container Elements 210
7.11 A Brief Intro to Pointer-Based Strings 216
7.12 Looking Ahead to Other Pointer Topics 220
7.13 Wrap-Up 220

Chapter 8: strings, string_views, Text Files, CSV Files and Regex 221
8.1 Introduction 222
8.2 string Assignment and Concatenation 223
8.3 Comparing strings 225
8.4 Substrings 226
8.5 Swapping strings 227
8.6 string Characteristics 227
8.7 Finding Substrings and Characters in a string 230
8.8 Replacing and Erasing Characters in a string 232
8.9 Inserting Characters into a string 234
8.10 C++11 Numeric Conversions 235
8.11 C++17 string_view 236
8.12 Files and Streams 239
8.13 Creating a Sequential File 240
8.14 Reading Data from a Sequential File 243
8.15 C++14 Reading and Writing Quoted Text 245
8.16 Updating Sequential Files 246
8.17 String Stream Processing 247
8.18 Raw String Literals 249
8.19 Objects-Natural Case Study: Reading and Analyzing a CSV File Containing Titanic Disaster Data 250
8.20 Objects-Natural Case Study: Intro to Regular Expressions 259
8.21 Wrap-Up 267

Chapter 9: Custom Classes 269
9.1 Introduction 270
9.2 Test-Driving an Account Object 271
9.3 Account Class with a Data Member and Set and Get Member Functions 272
9.4 Account Class: Custom Constructors 275
9.5 Software Engineering with Set and Get Member Functions 279
9.6 Account Class with a Balance 280
9.7 Time Class Case Study: Separating Interface from Implementation 283
9.8 Compilation and Linking Process 290
9.9 Class Scope and Accessing Class Members 291
9.10 Access Functions and Utility Functions 292
9.11 Time Class Case Study: Constructors with Default Arguments 292
9.12 Destructors 298
9.13 When Constructors and Destructors Are Called 298
9.14 Time Class Case Study: A Subtle Trap—Returning a Reference or a Pointer to a private Data Member 302
9.15 Default Assignment Operator 304
9.16 const Objects and const Member Functions 306
9.17 Composition: Objects as Members of Classes 308
9.18 friend Functions and friend Classes 313
9.19 The this Pointer 314
9.20 static Class Members: Classwide Data and Member Functions 320
9.21 Aggregates in C++20 324
9.22 Objects-Natural Case Study: Serialization with JSON 326
9.23 Wrap-Up 333

Chapter 10: OOP: Inheritance and Runtime Polymorphism 335
10.1 Introduction 336
10.2 Base Classes and Derived Classes 339
10.3 Relationship Between Base and Derived Classes 341
10.4 Constructors and Destructors in Derived Classes 349
10.5 Intro to Runtime Polymorphism: Polymorphic Video Game 350
10.6 Relationships Among Objects in an Inheritance Hierarchy 351
10.7 Virtual Functions and Virtual Destructors 357
10.8 Abstract Classes and Pure virtual Functions 362
10.9 Case Study: Payroll System Using Runtime Polymorphism 363
10.10 Runtime Polymorphism, Virtual Functions and Dynamic Binding "Under the Hood" 373
10.11 Non-Virtual Interface (NVI) Idiom 376
10.12 Program to an Interface, Not an Implementation 383
10.13 Runtime Polymorphism with std::variant and std::visit 391
10.14 Multiple Inheritance 397
10.15 protected Class Members: A Deeper Look 405
10.16 public, protected and private Inheritance 406
10.17 More Runtime Polymorphism Techniques; Compile-Time Polymorphism 408
10.18 Wrap-Up 412

Chapter 11: Operator Overloading, Copy/Move Semantics and Smart Pointers 415
11.1 Introduction 416
11.2 Using the Overloaded Operators of Standard Library Class string 418
11.3 Operator Overloading Fundamentals 423
11.4 (Downplaying) Dynamic Memory Management with new and delete 425
11.5 Modern C++ Dynamic Memory Management: RAII and Smart Pointers 427
11.6 MyArray Case Study: Crafting a Valuable Class with Operator Overloading 430
11.7 C++20 Three-Way Comparison Operator (<=>) 459
11.8 Converting Between Types 462
11.9 explicit Constructors and Conversion Operators 463
11.10 Overloading the Function Call Operator () 466
11.11 Wrap-Up 466

Chapter 12: Exceptions and a Look Forward to Contracts 467
12.1 Introduction 468
12.2 Exception-Handling Flow of Control 471
12.3 Exception Safety Guarantees and noexcept 476
12.4 Rethrowing an Exception 477
12.5 Stack Unwinding and Uncaught Exceptions 479
12.6 When to Use Exception Handling 481
12.7 Constructors, Destructors and Exception Handling 483
12.8 Processing new Failures 487
12.9 Standard Library Exception Hierarchy 490
12.10 C++'s Alternative to the finally Block: Resource Acquisition Is Initialization (RAII) 493
12.11 Some Libraries Support Both Exceptions and Error Codes 493
12.12 Logging 494
12.13 Looking Ahead to Contracts 495
12.14 Wrap-Up 503

Chapter 13: Standard Library Containers and Iterators 505
13.1 Introduction 506
13.2 Introduction to Containers 508
13.3 Working with Iterators 513
13.4 A Brief Introduction to Algorithms 518
13.5 Sequence Containers 518
13.6 vector Sequence Container 519
13.7 list Sequence Container 526
13.8 deque Sequence Container 531
13.9 Associative Containers 533
13.10 Container Adaptors 543
13.11 bitset Near Container 547
13.12 Optional: A Brief Intro to Big O 549
13.13 Optional: A Brief Intro to Hash Tables 552
13.14 Wrap-Up 553

Chapter 14: Standard Library Algorithms and C++20 Ranges & Views 555
14.1 Introduction 556
14.2 Algorithm Requirements: C++20 Concepts 558
14.3 Lambdas and Algorithms 560
14.4 Algorithms 563
14.5 Function Objects (Functors) 603
14.6 Projections 608
14.7 C++20 Views and Functional-Style Programming 611
14.8 Intro to Parallel Algorithms 617
14.9 Standard Library Algorithm Summary 619
14.10 A Look Ahead to C++23 Ranges 622
14.11 Wrap-Up 623

Chapter 15: Templates, C++20 Concepts and Metaprogramming 625
15.1 Introduction 626
15.2 Custom Class Templates and Compile-Time Polymorphism 629
15.3 C++20 Function Template Enhancements 634
15.4 C++20 Concepts: A First Look 636
15.5 Type Traits 644
15.6 C++20 Concepts: A Deeper Look 648
15.7 Testing C++20 Concepts with static_assert 659
15.8 Creating a Custom Algorithm 661
15.9 Creating a Custom Container and Iterators 663
15.10 Default Arguments for Template Type Parameters 678
15.11 Variable Templates 678
15.12 Variadic Templates and Fold Expressions 679
15.13 Template Metaprogramming 693
15.14 Wrap-Up 705

Chapter 16: C++20 Modules: Large-Scale Development 707
16.1 Introduction 708
16.2 Compilation and Linking Before C++20 710
16.3 Advantages and Goals of Modules 711
16.4 Example: Transitioning to Modules—Header Units 712
16.5 Modules Can Reduce Translation Unit Sizes and Compilation Times 715
16.6 Example: Creating and Using a Module 716
16.7 Global Module Fragment 724
16.8 Separating Interface from Implementation 725
16.9 Partitions 732
16.10 Additional Modules Examples 740
16.11 Migrating Code to Modules 746
16.12 Future of Modules and Modules Tooling 746
16.13 Wrap-Up 748

Chapter 17: Parallel Algorithms and Concurrency: A High-Level View 755
17.1 Introduction 756
17.2 Standard Library Parallel Algorithms (C++17) 759
17.3 Multithreaded Programming 767
17.4 Launching Tasks with std::jthread 771
17.5 Producer–Consumer Relationship: A First Attempt 776
17.6 Producer–Consumer: Synchronizing Access to Shared Mutable Data 783
17.7 Producer–Consumer: Minimizing Waits with a Circular Buffer 795
17.8 Readers and Writers 804
17.9 Cooperatively Canceling jthreads 805
17.10 Launching Tasks with std::async 808
17.11 Thread-Safe, One-Time Initialization 815
17.12 A Brief Introduction to Atomics 816
17.13 Coordinating Threads with C++20 Latches and Barriers 820
17.14 C++20 Semaphores 826
17.15 C++23: A Look to the Future of C++ Concurrency 830
17.16 Wrap-Up 831

Chapter 18: C++20 Coroutines 833
18.1 Introduction 834
18.2 Coroutine Support Libraries 835
18.3 Installing the concurrencpp and generator Libraries 837
18.4 Creating a Generator Coroutine with co_yield and the generator Library 837
18.5 Launching Tasks with concurrencpp 841
18.6 Creating a Coroutine with co_await and co_return 845
18.7 Low-Level Coroutines Concepts 853
18.8 C++23 Coroutines Enhancements 855
18.9 Wrap-Up 856

Appendix A: Operator Precedence and Grouping 857

Appendix B: Character Set 859

Index 861

Online Chapters and Appendices
Chapter 19: Stream I/O and C++20 Text Formatting
Chapter 20: Other Topics and a Look Toward the Future of C++
Appendix C: Number Systems
Appendix D: Preprocessor
Appendix E: Bit Manipulation

Editorial Reviews

From Marc Gregoire, Software Architect, Nikon Metrology, Microsoft Visual C++ MVP and Author of Professional C++, 5/e:
"C++20 is a big update for the C++ language and its standard library, introducing numerous new features. Some of these will drastically change the way we write and organize our code. C++20 for Programmers is a great book to learn C++. This latest edition is updated to include new C++20 features bringing you up to speed with writing modern and well-structured C++ code. Everything is introduced in an easy-to-read, step-by-step manner with the aid of compact, to-the-point code examples. I like the objects-natural approach and examples. For example, the ZIP discussion shows how powerful it is to use third-party libraries that implement complicated things—this allows you to write and read ZIP files in just a few lines of your own code. Another very nice and interesting objects-natural example shows encrypting and decrypting text with just a few lines of code."

"I especially like that you've stressed to avoid using pointers but instead use modern functionality such as std::array, std::vector, std::string, and so on. I also like the very nice objects natural section, explaining std::span. A nice introduction to containers, iterators, and algorithms, the range-based for loop, and functional programming. Good introduction to classes. Good discussion of modern runtime- and compile-time polymorphism techniques. A very good chapter on operator overloading. Nice exceptions chapter—I like the look ahead to contracts for C++23 or later! I like the chapter 'Templates, C++20 Concepts and Metaprogramming.' It touches on several more advanced features, but it is still easy to read and to follow the examples. Nice chapter on C++20 modules—it contains just the right amount of details for this book."

From Dr. Daisy Hollman, ISO C++ Standards Committee Member:
"I'm a big fan of talking about objects early and often—it's nice to see that my pedagogical instincts in this matter are supported by at least some experts. :-) I love the emphasis on code readability throughout. The emphasis on safe programming in this book is excellent. I really like the 'objects natural' case study with the zip library. I'm a big fan of introducing the class template array before the language version of arrays, and I also like the use of vector as a case study. I absolutely love the emphasis on avoiding pointers. Well done! I'm also a big fan of the section on span. The use of std::string_view in Figure 9.2 is exactly what we had in mind when we designed it."

"In the chapter, 'OOP: Inheritance and Runtime Polymorphism,' it's awesome that NVI (non-virtual interface idiom) is covered. I really like the discussion of real-world consequences of implementation inheritance. 'Operator Overloading, Copy/Move Semantics and Smart Pointers' is a great chapter."

From Inbal Levi, SolarEdge Technologies, ISO C++ Foundation director, ISO C++ SG9 (Ranges) chair, ISO C++ Standards Committee:
" C++20 for Programmers provides a great introduction to C++20 through simple and useful examples. 'C++20 formatting with the {fmt} library' is a great and important explanation—it clarifies the relation between standard library implementations and open-source libraries. Examples (especially cryptography) in the 'Functions and an Intro to Function Templates' chapter are great. The chapter, 'Strings, string_views, Text Files, CSV Files and Regex' is well written, great examples. I think both the use case and the reference to OWASP (Open Web Application Security Project) as a knowledge resource will do a great deal for the new developer. The chapter 'OOP: Inheritance and Runtime Polymorphism,' presents some very interesting design patterns. The chapter, 'Operator Overloading, Copy/Move Semantics and Smart Pointers,' is great, the explanations and example class are good and informative."

From Danny Kalev, Ph.D. and Certified System Analyst and Software Engineer, Former ISO C++ Standards Committee Member:
"The Deitels have included all of the useful new C++20 features in a readable and up-to-date book with numerous code examples aimed to transport you swiftly and smoothly into the era of Modern C++ programming. The code has been rigorously tested with three leading compilers. Covers the latest C++20 programming and design idioms. All the relevant hands-on knowledge for designing efficient and reusable concurrent C++20 apps."

"The chapter, 'Strings, string_views, Text Files, CSV Files and Regex,' is one of the best chapters in any C++ book I've read. Kudos on the Titanic dataset. 'Operator Overloading, Copy/Move Semantics and Smart Pointers' discusses the Special Five member functions, emphasizing the differences between copy constructors and assignment operators, and between copying and moving. The chapter, 'Standard Library Containers and Iterators,' covers the major concepts of standard library containers, iterators, algorithms and container adaptors—all with C++20-compliant code. The chapter, 'Standard Library Algorithms and C++20 Ranges & Views,' covers advanced C++20 features, including iterators and their requirements, the C++20 ranges facilities and related algorithms, functional programming using functors and lambdas, and brief discussion about parallelization. 'Templates, C++20 Concepts and Metaprogramming' is one of the best chapters of this book. Not only is it clear and easy to read, it's also up to date with the latest C++20 features. The new C++20 concepts are explained and demonstrated very well, as are variadic templates, the more traditional notion of type traits and finally, the pick of the crop is template metaprogramming. Writing about modules is quite a challenge—this chapter presents them clearly and in detail. I loved the jaw-dropping improvement in translation unit sizes achieved by importing a header unit using C++20 modules rather than the preprocessor to include a header."

"Coroutines, one of C++20's 'big four' features, are explained clearly. The main concepts associated with coroutines, i.e., co_await, co_yield and co_return, are demonstrated using easy-to-follow code listings, as are more advanced issues such as tasks and executors. Another noteworthy point is the balanced coverage of third-party coroutines support libraries, since C++20 doesn't provide its own yet."

From Arthur O'Dwyer, C++ trainer, Chair of CppCon's Back to Basics track, author of several accepted C++17/20/23 proposals and the book Mastering the C++17 STL:
"The chapter, 'OOP: Inheritance and Runtime Polymorphism,' is thorough on all the permutations of private, public, data members, function members, virtual, non-virtual, etc. Very obviously concerned with being up-to-date with C++17 and C++20—that's excellent! You emphasize override and final, which is good. You also emphasize 'prefer composition over inheritance' and NVI (non-virtual interface idiom), which I like. I'm very happy that you show the new ways and say they're good. That's great. C++20 Modules are relegated to their own chapter near the end of the book, but their treatment is not superficial; the chapter demonstrates some non-trivial features such as module partitions, and includes step-by-step instructions for building the sample code on all three mainstream implementations. Covers C++20 Concepts and Ranges confidently and in depth. New features such as std::format, std::span and concepts are used heavily throughout the code examples. The fun part of the chapter, 'Control Statements: Part 1,' is integrating the third-party libraries <bignumber.h> [in the objects-natural case study] and <fmt/format.h>. 'Strings, string_views, Text Files, CSV Files and Regex' is a solid chapter. I like presenting string and string_view together as a unit. The rapidcsv [objects-natural] case study is a really good idea. The chapter 'Exceptions and a Look Forward to Contracts' presents a pretty clear narrative focus on exceptions and error handling. In the chapter 'C++20 Coroutines,' the choice to use tl::generator and concurrencpp::result is good."

From José Antonio González Seco, Parliament of Andalusia:
"Ideal for professionals who want to learn modern C++ or improve their skills with it. Covers C++20 in a clear and practical way, with an impressive amount of high-quality references, a strong focus on performance and security, and an 'objects natural' approach very useful for learning how to integrate external libraries in your projects. Great coverage of modules, with clear explanations."

From Saar Raz, Senior Software Engineer, Swimm.io and Implementor of C++20 Concepts in Clang:
"The chapter 'Templates, C++20 Concepts and Metaprogramming' covers a lot of ground and important features, such as concept-based overloading, fold expressions and constexpr if. It also goes into great detail explaining how the metaprogramming works. The explanation about the need for coroutines is excellent and provides many use cases, building a strong case for the feature. Gives a high level of understanding of the main low-level concepts of coroutine implementation—it helped me better grasp those concepts."

From Anthony Williams, Member of the British Standards Institution C++ Standards Panel, Director of Just Software Solutions Ltd., Author of C++ Concurrency in Action, 2/e:
"Gives concrete information on how to write code using modules. I like that the chapter 'Parallel Algorithms and Concurrency: A High-Level View' doesn't go too deep on the lower-level things and starts with the parallel algorithms. Introduces coroutines clearly, with simple examples using open-source libraries."

From Andreas Fertig, Independent C++ Trainer and Consultant, Creator of cppinsights.io, Author of Programming with C++20:
"Paul and Harvey do an excellent job teaching modern C++ using C++20. Templates are a huge beast and the chapter 'Templates, C++20 Concepts and Metaprogramming' gives a good overview. The chapter 'C++20 Modules: Large-Scale Development' is a good write-up of modules and how they work—it covers all the parts one needs to start with or convert to modules. An excellent introduction to multithreading and concurrency. In the chapter 'C++20 Coroutines,' I especially liked the overview of coroutine use-cases."

Some Reviews from Earlier Editions—and the Reviewers' Affiliations at the Time
"A great introduction to object-oriented programming in C++. I wish I'd had it when I was learning the language. Provides helpful tips that are relevant to real problems in the software industry." —Gordon Hogenson, Microsoft

"I like how the text emphasizes the importance of style, comments and consistency." —Renato Golin, LLVM Compiler Engineer (now a Senior Research Engineer at Microsoft)

"A stellar overview of how polymorphism works—the section on how it's done is great." —Gašper Ažman, A9.com Search Technologies and Co-author, C++ Today: The Beast Is Back

"Gets you into C++ programming quickly with important tips, loads of insights and gradual progression towards advanced concepts. A great tour of C++ for beginners learning an industrial-strength programming language." —Dean Michael Berris, Google, Maintainer of cpp-netlib and Former ISO C++ Committee Member (now a Principal Software Engineer at Microsoft)

"I liked that the material doesn't skirt around the complex nature of C++, and instead explains all the aspects of the example programs." —Jonathan Wakely, Redhat, ISO C++ Committee Secretary

From the Publisher