Book Image

C++20 STL Cookbook

By : Bill Weinman
Book Image

C++20 STL Cookbook

By: Bill Weinman

Overview of this book

Fast, efficient, and flexible, the C++ programming language has come a long way and is used in every area of the industry to solve many problems. The latest version C++20 will see programmers change the way they code as it brings a whole array of features enabling the quick deployment of applications. This book will get you up and running with using the STL in the best way possible. Beginning with new language features in C++20, this book will help you understand the language's mechanics and library features and offer insights into how they work. Unlike other books, the C++20 STL Cookbook takes an implementation-specific, problem-solution approach that will help you overcome hurdles quickly. You'll learn core STL concepts, such as containers, algorithms, utility classes, lambda expressions, iterators, and more, while working on real-world recipes. This book is a reference guide for using the C++ STL with its latest capabilities and exploring the cutting-edge features in functional programming and lambda expressions. By the end of the book C++20 book, you'll be able to leverage the latest C++ features and save time and effort while solving tasks elegantly using the STL.
Table of Contents (13 chapters)

Use compile-time vectors and strings with constexpr

C++20 allows the use of constexpr in several new contexts. This provides improved efficiency, in that these things may be evaluated at compile time, instead of run time.

How to do it…

The specification includes the ability to use string and vector objects in constexpr context. It's important to note that these objects may not themselves be declared constexpr, but they may be used in a compile-time context:

constexpr auto use_string() {
    string str{"string"};
    return str.size();

You can also use algorithms in constexpr context:

constexpr auto use_vector() {
    vector<int> vec{ 1, 2, 3, 4, 5};
    return accumulate(begin(vec), end(vec), 0);

The result of the accumulate algorithm is available at compile time and in constexpr context.

How it works…

The constexpr specifier declares...