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)

List files in a directory

The filesystem library provides a directory_entry class with directory-related information about a given path. We can use this to create useful directory listings.

How to do it…

In this recipe, we create a directory listing utility using the information in the directory_entry class:

  • We start with our namespace alias and formatter specialization for displaying path objects:
    namespace fs = std::filesystem;
    struct std::formatter<fs::path>: std::formatter<std::string> {
        template<typename FormatContext>
        auto format(const fs::path& p, FormatContext& ctx) {
            return format_to(ctx.out(), "{}", p.string());
  • The directory_iterator class makes it easy to list a directory:
    int main() {
        constexpr const char* fn{ "." };