Book Image

Modern C++: Efficient and Scalable Application Development

By : Richard Grimes, Marius Bancila
Book Image

Modern C++: Efficient and Scalable Application Development

By: Richard Grimes, Marius Bancila

Overview of this book

C++ is one of the most widely used programming languages. It is fast, flexible, and used to solve many programming problems. This Learning Path gives you an in-depth and hands-on experience of working with C++, using the latest recipes and understanding most recent developments. You will explore C++ programming constructs by learning about language structures, functions, and classes, which will help you identify the execution flow through code. You will also understand the importance of the C++ standard library as well as memory allocation for writing better and faster programs. Modern C++: Efficient and Scalable Application Development deals with the challenges faced with advanced C++ programming. You will work through advanced topics such as multithreading, networking, concurrency, lambda expressions, and many more recipes. By the end of this Learning Path, you will have all the skills to become a master C++ programmer. This Learning Path includes content from the following Packt products: • Beginning C++ Programming by Richard Grimes • Modern C++ Programming Cookbook by Marius Bancila • The Modern C++ Challenge by Marius Bancila
Table of Contents (24 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
12
Math Problems
13
Language Features
14
Strings and Regular Expressions
15
Streams and Filesystems
16
Date and Time
17
Algorithms and Data Structures
Index

Using string_view instead of constant string references


When working with strings, temporary objects are created all the time, even if you might not be really aware of it. Many times the temporary objects are irrelevant and only serve the purpose of copying data from one place to another (for example, from a function to its caller). This represents a performance issue because they require memory allocation and data copying, which is desirable to be avoided. For this purpose, the C++17 standard provides a new string class template called std::basic_string_view that represents a non-owning constant reference to a string (that is, a sequence of characters). In this recipe, you will learn when and how you should use this class.

Getting ready

The string_view class is available in the namespace std in the string_view header.

How to do it...

You should use std::string_view to pass a parameter to a function (or return a value from a function), instead of std::string const & unless your code needs...