Clean C++20 : Sustainable Software Development Patterns and Best Practices

Write maintainable, extensible, and durable software with modern C++. This book, updated for the recently released C++20 standard, is a must for every developer, software architect, or team leader who is interested in well-crafted C++ code, and thus also wants to save development costs. If you want to teach yourself about writing better C++ code, __Clean C++20__ is exactly what you need. It is written for C++ developers of all skill levels and shows by example how to write understandable, flexible, maintainable, and efficient C++ code. Even if you are a seasoned C++ developer, there are nuggets and data points in this book that you will find useful in your work. If you don't take care with your codebase, you can produce a large, messy, and unmaintainable beast in any programming language. However, C++ projects in particular are prone to get messy and tend to slip into a maintenance nightmare. There is lots of C++ code out there that looks as if it was written in the 1980s, completely ignoring principles and practices of well-written and modern C++. It seems that C++ developers have been forgotten by those who preach Software Craftsmanship and Clean Code principles. The web is full of C++ code examples that may be very fast and highly optimized, but whose developers have completely ignored elementary principles of good design and well-written code. This book will explain how to avoid this and how to get the most out of your C++ code. You'll find your coding becomes more efficient and, importantly, more fun. **What You Will Learn*** Gain sound principles and rules for clean coding in C++ * Carry out test-driven development (TDD) * Better modularize your C++ code base * Discover and apply C++ design patterns and idioms * Write C++ code in both object-oriented and functional programming styles **Who This Book Is For** Any C++ developer or software engineer with an interest in producing better code. Table of Contents About the Author About the Technical Reviewer Acknowledgments Chapter 1: Introduction Software Entropy Why C++? Clean Code C++11: The Beginning of a New Era Who This Book Is For Conventions Used in This Book Sidebars Notes, Tips, and Warnings Code Samples Coding Style C++ Core Guidelines Companion Website and Source Code Repository UML Diagrams Chapter 2: Build a Safety Net The Need for Testing Introduction to Testing Unit Tests What About QA? Rules for Good Unit Tests Test Code Quality Unit Test Naming Unit Test Independence One Assertion per Test Independent Initialization of Unit Test Environments Exclude Getters and Setters Exclude Third-Party Code Exclude External Systems What Do We Do with the Database? Don’t Mix Test Code with Production Code Tests Must Run Fast How Do You Find a Test’s Input Data? Equivalence Partitioning Boundary Value Analysis Test Doubles (Fake Objects) Chapter 3: Be Principled What Is a Principle? KISS YAGNI DRY It’s About Knowledge! Building Abstractions Is Sometimes Hard Information Hiding Strong Cohesion Loose Coupling Be Careful with Optimizations Principle of Least Astonishment (PLA) The Boy Scout Rule Collective Code Ownership Chapter 4: Basics of Clean C++ Good Names Names Should Be Self-Explanatory Use Names from the Domain Choose Names at an Appropriate Level of Abstraction Avoid Redundancy When Choosing a Name Avoid Cryptic Abbreviations Avoid Hungarian Notation and Prefixes Avoid Using the Same Name for Different Purposes Comments Let the Code Tell the Story Do Not Comment Obvious Things Don’t Disable Code with Comments Don’t Write Block Comments Don’t Use Comments to Substitute Version Control The Rare Cases Where Comments Are Useful Documentation Generation from Source Code Functions One Thing, No More! Let Them Be Small “But the Call Time Overhead!” Function Naming Use Intention-Revealing Names Parameters and Return Values Number of Parameters Avoid Flag Parameters Avoid Output Parameters Don’t Pass or Return 0 (NULL, nullptr) Strategies for Avoiding Regular Pointers Choose simple object construction on the stack instead of on the heap In a function’s argument list, use (const) references instead of pointers If it is inevitable to deal with a pointer to a resource, use a smart one If an API returns a raw pointer... The Power of const Correctness About Old C-Style in C++ Projects Choose C++ Strings and Streams over Old C-Style char* Avoid Using printf(), sprintf(), gets(), etc. Choose Standard Library Containers over Simple C-Style Arrays Use C++ Casts Instead of Old C-Style Casts Avoid Macros Chapter 5: Advanced Concepts of Modern C++ Managing Resources Resource Acquisition Is Initialization (RAII) Smart Pointers Unique Ownership with std::unique_ptr Shared Ownership with std::shared_ptr No Ownership, but Secure Access with std::weak_ptr Atomic Smart Pointers Avoid Explicit New and Delete Managing Proprietary Resources We Like to Move It What Are Move Semantics? The Matter with Those lvalues and rvalues rvalue References Don’t Enforce Move Everywhere The Rule of Zero The Compiler Is Your Colleague Automatic Type Deduction Computations During Compile Time Variable Templates Don’t Allow Undefined Behavior Type-Rich Programming Know Your Libraries Take Advantage of Easier Parallelization of Algorithms Since C++17 Sorting and Output of a Container More Convenience with Ranges Non-Owning Ranges with Views Comparing Two Sequences Take Advantage of Boost More Libraries That You Should Know About Proper Exception and Error Handling Prevention Is Better Than Aftercare No Exception Safety Basic Exception Safety Strong Exception Safety The No-Throw Guarantee An Exception Is an Exception, Literally! If You Can’t Recover, Get Out Quickly Define User-Specific Exception Types Throw by Value, Catch by const Reference Pay Attention to the Correct Order of Catch Clauses Interface Design Attributes noreturn (since C++11) deprecated (since C++14) nodiscard (since C++17) maybe_unused (since C++17) Concepts: Requirements for Template Arguments Specifying a Concept Applying a Concept Chapter 6: Modularization The Basics of Modularization Criteria for Finding Modules Focus on the Domain of Your Software Abstraction Choose a Hierarchical Decomposition Single Responsibility Principle (SRP) Single Level of Abstraction (SLA) The Whole Enchilada Object-Orientation Object-Oriented Thinking Principles for Good Class Design Keep Classes Small Open-Closed Principle (OCP) A Short Comparison of Type Erasure Techniques Liskov Substitution Principle (LSP) The Square-Rectangle Dilemma Favor Composition over Inheritance Interface Segregation Principle (ISP) Acyclic Dependency Principle Dependency Inversion Principle (DIP) Don’t Talk to Strangers (The Law of Demeter) Avoid Anemic Classes Tell, Don’t Ask! Avoid Static Class Members Modules The Drawbacks of #include Modules to the Rescue Under the Hood Three Options for Using Modules Include Translation Header Importation Module Importation Separating Interface and Implementation The Impact of Modules Chapter 7: Functional Programming What Is Functional Programming? What Is a Function? Pure vs Impure Functions Functional Programming in Modern C++ Functional Programming with C++ Templates Function-Like Objects (Functors) Generator Unary Function Predicate Binary Functors Binders and Function Wrappers Lambda Expressions Generic Lambda Expressions (C++14) Lambda Templates (C++20) Higher-Order Functions Map, Filter, and Reduce Map Filter Reduce (Fold) Fold Expressions in C++17 Pipelining with Range Adaptors (C++20) Clean Code in Functional Programming Chapter 8: Test-Driven Development The Drawbacks of Plain Old Unit Testing (POUT) Test-Driven Development as a Game Changer The Workflow of TDD TDD by Example: The Roman Numerals Code Kata Preparations The First Test The Second Test The Third Test and the Tidying Afterward More Sophisticated Tests with a Custom Assertion It’s Time to Clean Up Again Approaching the Finish Line Done! The Advantages of TDD When We Should Not Use TDD TDD Is Not a Replacement for Code Reviews Chapter 9: Design Patterns and Idioms Design Principles vs Design Patterns Some Patterns and When to Use Them Dependency Injection (DI) The Singleton Anti-Pattern Dependency Injection to the Rescue Adapter Strategy Command Command Processor Composite Observer Factories Simple Factory Facade The Money Class Special Case Object (Null Object) What Is an Idiom? Some Useful C++ Idioms The Power of Immutability Substitution Failure Is Not an Error (SFINAE) The Copy-and-Swap Idiom Pointer to Implementation (PIMPL) Appendix A: Small UML Guide Structural Modeling Component Class and Object Interface Association Generalization Dependency Template and Template Binding Behavioral Modeling Activity Diagram Action Control Flow Edge Other Activity Nodes Sequence Diagram Lifeline Message State Diagram State Transitions External Transitions Internal Transitions Trigger Stereotypes Bibliography Index Write maintainable, extensible, and durable software with modern C . This book, updated for the recently released C 20 standard, is a must for every developer, software architect, or team leader who is interested in well-crafted C code, and thus also wants to save development costs. If you want to teach yourself about writing better C code, Clean C 20 is exactly what you need. It is written for C developers of all skill levels and shows by example how to write understandable, flexible, maintainable, and efficient C code. Even if you are a seasoned C developer, there are nuggets and data points in this book that you will find useful in your work. If you don't take care with your codebase, you can produce a large, messy, and unmaintainable beast in any programming language. However, C projects in particular are prone to get messy and tend to slip into a maintenance nightmare. There is lots of C code out there that looks as if it was written in the 1980s, completely ignoring principles and practices of well-written and modern C . It seems that C developers have been forgotten by those who preach Software Craftsmanship and Clean Code principles. The web is full of C code examples that may be very fast and highly optimized, but whose developers have completely ignored elementary principles of good design and well-written code. This book will explain how to avoid this and how to get the most out of your C code. You'll find your coding becomes more efficient and, importantly, more fun. What You Will Learn Gain sound principles and rules for clean coding in C Carry out test-driven development (TDD) Better modularize your C code base Discover and apply C design patterns and idioms Write C code in both object-oriented and functional programming styles Who This Book Is For Any C developer or software engineer with an interest in producing better code. Write maintainable, extensible, and durable software with modern C++. This book, updated for the recently released C++20 standard, is a must for every developer, software architect, or team leader who is interested in well-crafted C++ code, and thus also wants to save development costs. If you want to teach yourself about writing better C++ code, Clean C++20 is exactly what you need. It is written for C++ developers of all skill levels and shows by example how to write understandable, flexible, maintainable, and efficient C++ code. Even if you are a seasoned C++ developer, there are nuggets and data points in this book that you will find useful in your work. If you don't take care with your codebase, you can produce a large, messy, and unmaintainable beast in any programming language. However, C++ projects in particular are prone to get messy and tend to slip into a maintenance nightmare. There is lots of C++ code out there that looks as if it was written in the 1980s, completely ignoring principles and practices of well-written and modern C++. It seems that C++ developers have been forgotten by those who preach Software Craftsmanship and Clean Code principles. The web is full of C++ code examples that may be very fast and highly optimized, but whose developers have completely ignored elementary principles of good design and well-written code. This book will explain how to avoid this and how to get the most out of your C++ code. You'll find your coding becomes more efficient and, importantly, more fun. You will: Gain sound principles and rules for clean coding in C++ ; Learn and carry out test-driven development (TDD) ; Learn principles for a better modularize your C++ code base ; Discover and apply C++ design patterns and idioms ; Learn how to write C++ code in an object-oriented, as well as in a functional programming style Write Maintainable, Extensible, And Durable Software With Modern C++. This Book, Updated For The C++20 Standard, Is A Must For Every Developer, Software Architect, Or Team Leader Who Is Interested In Good C++ Code, And Thus Also Wants To Save Development Costs. If You Want To Teach Yourself About Writing Clean C++, Clean C++ Is Exactly What You Need. It Is Written To Help C++ Developers Of All Skill Levels And Shows By Example How To Write Understandable, Flexible, Maintainable, And Efficient C++ Code. Even If You Are A Seasoned C++ Developer, There Are Nuggets And Data Points In This Book That You Will Find Useful In Your Work. If You Don't Take Care With Your Code, You Can Produce A Large, Messy, And Unmaintainable Beast In Any Programming Language. However, C++ Projects In Particular Are Prone To Be Messy And Tend To Slip Into Bad Habits. Lots Of C++ Code That Is Written Today Looks As If It Was Written In The 1980s. It Seems That C++ Developers Have Been Forgotten By Those Who Preach Software Craftsmanship And Clean Code Principles. The Web Is Full Of Bad, But Apparently Very Fast And Highly Optimized C++ Code Examples, With Cruel Syntax That Completely Ignores Elementary Principles Of Good Design And Well-written Code. This Book Will Explain How To Avoid This Scenario And How To Get The Most Out Of Your C++ Code. You'll Find Your Coding Becomes More Efficient And, Importantly, More Fun. What You'll Learn Gain Sound Principles And Rules For Clean Coding In C++ Carry Out Test Driven Development (tdd) Discover C++ Design Patterns And Idioms Apply These Design Patterns Who This Book Is For Any C++ Developer Or Software Engineer With An Interest In Producing Better Code.