0% completed

All LessonsFree Lessons (13)

Introduction

About This Course

New C++20 Features

Chapter Overview Format Text with the New Format Library Use Compile-Time Vectors and Strings with Constexpr Safely Compare Integers of Different Types Use the Spaceship Operator <=> for Three-Way Comparisons Easily Find Feature Test Macros with the <version> Header Create Safer Templates with Concepts and Constraints Avoid Re-Compiling Template Libraries with Modules Create Views into Containers with Ranges Quiz: C++20 Features

General STL Features

Chapter Overview Use the New Span Class to Make Our C-Arrays Safer Use Structured Binding to Return Multiple Values Initialize Variables within if and switch Statements Use Template Argument Deduction for Simplicity and Clarity Use If constexpr to Simplify Compile-Time Decisions Quiz: General STL Features Challenge: Make Our Code Safer and Easier to Read

STL Containers

Chapter Overview Use Uniform Erasure Functions to Delete Items from a Container Delete Items from an Unsorted Vector in Constant Time Access Vector Elements Directly and Safely Keep Vector Elements Sorted Efficiently Insert Elements into a Map Efficiently Modify the Keys of Map Items Use unordered_map with Custom Keys Use Set to Sort and Filter User Input A Simple RPN Calculator with Deque A Word Frequency Counter with Map Find Long Sentences with a Vector of Vectors A ToDo List Using Multimap Quiz: STL Containers Challenge: Let's Play with Containers

Compatible Iterators

Chapter Overview Iterators Are Fundamental Create an Iterable Range Make Our Iterators Compatible with STL Iterator Traits Use Iterator Adapters to Fill STL Containers Create a Generator as Iterators Use Reverse Iterator Adapters to Iterate Backward Iterate Objects of Unknown Length with a Sentinel Build a Zip Iterator Adapter Create a Random-Access Iterator Quiz: Compatible Iterators Challenge: Reverse Everything in a String

Lambda Expressions

Chapter Overview Lambda Expressions Use Lambdas for Scoped Reusable Code Use Lambdas as Predicates with the Algorithm Library Use std::function as a Polymorphic Wrapper Concatenate Lambdas with Recursion Combine Predicates with Logical Conjunction Call Multiple Lambdas with the Same Input Use Mapped Lambdas for a Jump Table Quiz: Lambda Expressions Challenge: Output with Lambda Expressions

STL Algorithms

Chapter Overview Copy from One Iterator to Another Join Container Elements into a String Sort Containers with std::sort()Modify Containers with std::transform Find Items in a Container Limit the Values of a Container to a Range with std::clamp Sample Data Sets with std::sample Generate Permutations of Data Sequences Merge Sorted Containers Quiz: STL Algorithms Challenge: Let's Dive into Algorithms

Strings, Streams, and Formatting

Chapter Overview Use string_view as a Lightweight String Object Concatenate Strings Transform Strings Format Text with C++20’s Format Library Trim Whitespace from Strings Read Strings from User Input Count Words in a File Initialize Complex Structures From File Input Customize a String Class With char_traits Parse Strings with Regular Expressions Quiz: Strings, Streams and Formatting Challenge: String With a Zero Space

Utility Classes

Chapter Overview

Manage Optional Values with std::optional

Use std::any for Type Safety

Store Different Types with std::variant

Time Events with std::chrono

Use Fold Expressions for Variadic Tuples

Manage Allocated Memory with std::unique_ptr

Share Objects with std::shared_ptr

Use Weak Pointers with Shared Objects

Share Members of a Managed Object

Compare Random Number Engines

Compare Random Number Distribution Generators

Quiz: Utility Classes

Challenge: Let's Check Out the Type of Data

Concurrency and Parallelism

Chapter Overview Sleep for a Specific Amount of Time Use std::thread for Concurrency Use std::async for Concurrency Run STL Algorithms in Parallel with Execution Policies Share Data Safely with Mutex and Locks Share Flags and Values with std::atomic Initialize Threads with std::call_once Use std::condition_variable to Resolve the Producer-Consumer Quiz: Concurrency and Parallelism Challenge: Sleep in a Multithread Function Call

Using the File System

Chapter Overview Specialize std::formatter for the Path Class Use Manipulation Functions with Path List Files in a Directory Search Directories and Files With a Grep Utility Rename Files with Regex and directory_iterator Create a Disk Usage Counter Quiz: Usage of the File System Challenge: What's Inside a Path?

A Few More Ideas

Chapter Overview Create a Trie Class for Search Suggestions Implement Multiple Producers and Consumers Calculate the Error Sum of Two Vectors Build Our Own Algorithm: Split Leverage Existing Algorithms: Gather Remove Consecutive Whitespace Convert Numbers to Words Quiz: Trie, Gather Function, and White Space Removal Challenge: Remove Whatever is White!

Conclusion

C++20 STL Cookbook/

...

/

Use std::any for Type Safety

Use std::any for Type Safety

Learn to employ std::any for type safety.

We'll cover the following...

How to do it
How it works

Introduced with C++17, the std::any class provides a type-safe container for a single object of any type.

For example, this is a default-constructed any object:

any x{};

This object has no value. We can test that with the has_value() method:

if(x.has_value()) cout << "have value\n";
else cout << "no value\n";

Output:

no value

We assign a value to the any object with the assignment operator:

x = 42;

Now, the any object has a value, and a type:

if(x.has_value()) {
        cout << format("x has type: {}\n", x.type().name());
        cout << format("x has value: {}\n", any_cast<int>(x));
    } else {
        cout << "no value\n";
}

Output:

x has type: i
x has value: 42

The type() method returns a type_info object. The type_info::name() method returns an implementation-defined name for the type in a C-string. In this case, for GCC, the i means int. We use the any_cast< ...