C++ Lambda Story
C++ Lambda Story
Everything you need to know about Lambda Expressions in Modern C++!
About the Book
This book guides you through the evolution of C++ Lambda Expressions so that you can learn it step by step. We'll start with C++03 and a motivation to have "ad-hoc" functors, and then we'll move into the latest C++ standards:
- C++11 - early days of the feature. You'll learn about all the essential aspects of lambdas and several tricks you might apply. This is the longest chapter as we need to cover a lot of topics.
- C++14 - updates. See how to use generic lambdas and captures with an initialiser.
- C++17 - more improvements, especially by handling `this` pointer and allowing `constexpr`. You'll also learn about the overloaded pattern and how to derive from lambda.
- C++20 - in this section you'll see all of the new features adopted for C++20 like template lambdas and how to use them with concepts and constexpr algorithms.
Additionally, throughout the chapters, you'll learn about the following techniques:
- Immediately Invoked Functional Expressions (IIFE)
- How to instrument a default functor to gather extra information
- Replacing std::bind1st, std::bind2nd and removed functional stuff
- The Overloaded Pattern and how to inherit from a lambda
- Passing C++ captureless lambda as a function pointer to C API
- LIFTING with lambdas
- Storing lambdas in a container
- Variadic templates and arguments packs
- Lambdas and asynchronous execution
- and many more
While the book is 100% ready, I might release some "hot-fixes" smaller releases. All existing readers get new updates for free.
The book is inspired by two articles that appeared at cppstories.com:
The articles also are based on a live coding presentation given by C++ Expert Tomasz Kamiński at our local Cracow C++ User Group.
Readers Feedback & Reviews
Below, you can find the GoodReads page for the book with the readers' feedback:
And a review at Adam Sawicki Blog:
FAQ
I'm a beginner in C++? Is that book for me?
The book assumes that you have a basic knowledge of C++. I suggest taking some elementary course first.
I'm an expert, and I know everything about C++? Is that book for me?
Yeah... you know all about C++? Is this possible? :)
Anyway, in your case, the book will give you a good refresher and even will show you some new tricks.
I'm not a beginner nor an expert...?
Perfect! So the book will show you lots of examples that will expand your knowledge and also remind you things that you may already know.
Additionally, throughout the book, you'll see other techniques and features related to modern C++ like, `constexpr`, exceptions, fold expressions, `std::thread`, perfect forwarding using callable objects and many more.
Is this a historical book with lots of boring descriptions?
The flow of the book focuses on the background behind lambda expression and its evolution. But it's meant to teach you practical things. You'll learn the lambdas step by step, understanding new capabilities that lambdas got with each C++ revision.
Will I get free updates?
Yes! While the book is 100% ready, I might add some more updates in the future, mainly bug fixes.
That's why it's best to buy the book as early as possible; for example, the earliest version of the book was completely free.
The content looks like copied directly from the blog, so what's the point to buy it?
The very early version of the book was adapted directly from the blog... but then most of the content was rewritten and heavily updated. Now, you get at least 4x of what's available on the blog, not to mention the better quality and a nice-looking pdf/ebook (there's no need to click and jump between separate blog articles).
On the Internet there's lots of free content about lambdas, so why buy the book?
Sure! Even on my blog, you can find lots of articles about lambda expression. The C++ draft is also free, so you can read the specification on your own. Or have an additional explanation from great cppreference pages.
But the book will save you lots of your precious time looking for those quality content, extra examples, extended descriptions. What's more, by having a nice learning flow, you can understand this powerful C++ feature much faster at a super low price.
Is there a refund option?
Yes! if you buy the Book through Leanpub, then you have a 45-day guarantee. (Not applicable with Kindle direct Publishing though).
You can also download a preview with almost 60 pages.
Did I miss something?
If you have more questions, then please ask directly and write at bartek AT cppstories.com.
About the Author
Bundles that include this book
Reader Testimonials
Kobi
C++ Software Developer, San Diego
Just like in his previous book and his blog, Bartłomiej explains very well the details of lambda basics, the usage of lambda in your C++ code and goes all the way to the expert domain of this topic. Great read and very comprehensive (e)book to keep on your desk.
Jonathan Boccara
(fluentcpp.com)
This is a great piece of work, stuffed with details and practical examples, and very easy to read. A must-read to know how to make the most of lambdas in your C++ code.
Table of Contents
-
About the Book
- Roots Of The Book
- Who This Book is For
- How To Read This Book
- Reader Feedback & Errata
- Example Code
- Code License
-
Formatting And Special Sections
- Syntax Highlighting Limitations
- Special Sections
- Online Compilers
- About the Author
- Acknowledgements
- Revision History
-
1. Lambdas in C++98/03
-
Callable Objects in C++98/03
- What is a “Functor”?
- Issues with Function Object Class Types
- Composing With Functional Helpers
- Motivation for a New Feature
-
Callable Objects in C++98/03
-
2. Lambdas in C++11
-
The Syntax of Lambda Expression
- A Few Examples of Lambda Expressions
-
Core Definitions
- Compiler Expansion
-
The Type of a Lambda Expression
- Constructors and Copying
-
The Call Operator
- Overloading
- Attributes
- Other Modifiers
-
Captures
- Generated Code
- Capture All or Explicit?
-
The
mutableKeyword - Invocation Counter - An Example of Captured Variables
- Capturing Global Variables
- Capturing Statics
-
Capturing a Class Member And the
thisPointer - Moveable-only Objects
- Preserving Const
- Capturing a Parameter Pack
-
Return Type
- Trailing Return Type Syntax
-
Conversion to a Function Pointer
- A Tricky Case
-
IIFE - Immediately Invoked Functional Expression
- One Note About the Readability
- Inheriting from a Lambda
- Storing Lambdas in a Container
- Summary
-
The Syntax of Lambda Expression
-
3. Lambdas in C++14
- Default Parameters for Lambdas
- Return Type Deduction
-
Captures With an Initialiser
- Limitations
- Improvements for Existing Issues
-
Generic Lambdas
- Variadic Generic Arguments
- Perfect Forwarding with Generic Lambdas
- Deducing the Correct Type
-
Replacing
std::bind1standstd::bind2ndwith Lambdas- Using Modern C++ Techniques
- Function Composition
- LIFTing with lambdas
-
Recursive Lambdas
-
With
std::function - Internal Lambda and a Generic Parameter
- More Tricks
- Is a recursive lambda the best alternative?
-
With
- Summary
-
4. Lambdas in C++17
- Lambda Syntax Update
- Exception Specification in the Type System
-
constexprLambda Expressions- Examples
- Capturing Variables
-
constexprSummary:
-
Capture of
*this- Some Guides
- Updates To IIFE
- Extracting Functions with IIFE
- Updates to Variadic Generic Lambdas
-
Deriving from Multiple Lambdas
- Custom Template Argument Deduction Rules
- Extension to Aggregate Initialisation
-
Example with
std::variantandstd::visit
-
Concurrent Execution Using Lambdas
-
Lambdas with
std::thread -
Lambdas with
std::async - Lambdas and Parallel Algorithms from C++17
- Lambdas And Async - Wrap Up
-
Lambdas with
- Summary
-
5. Lambdas in C++20
- Lambda Syntax Update
- A Quick Overview of the Changes
-
constevalLambdas - Capturing a Parameter Pack
- Template Lambdas
- Concepts and Lambdas
-
Changes to Stateless Lambdas
- Even more with unevaluated contexts
-
Lambdas and
constexprAlgorithms - C++20 Updates to the Overloaded Pattern
- Summary
- Appendix A - List of Techniques
-
Appendix B - Six Advantages of C++ Lambda Expressions
- 1. Lambdas Make Code More Readable
-
2. Lambdas Can Compile 7x Faster than
std::bind! - 3. Lambdas Improve Locality of the Code
- 4. Lambdas Allow Storing State Easily
- 5. Lambdas Allow Several Overloads in the Same Place
- 6. Lambdas Get Better with Each Revision of C++!
- References
- Index
- Notes
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