Book Image

Modern C++ Programming Cookbook

By : Marius Bancila
Book Image

Modern C++ Programming Cookbook

By: Marius Bancila

Overview of this book

C++ is one of the most widely used programming languages. Fast, efficient, and flexible, it is used to solve many problems. The latest versions of C++ have seen programmers change the way they code, giving up on the old-fashioned C-style programming and adopting modern C++ instead. Beginning with the modern language features, each recipe addresses a specific problem, with a discussion that explains the solution and offers insight into how it works. You will learn major concepts about the core programming language as well as common tasks faced while building a wide variety of software. You will learn about concepts such as concurrency, performance, meta-programming, lambda expressions, regular expressions, testing, and many more in the form of recipes. These recipes will ensure you can make your applications robust and fast. By the end of the book, you will understand the newer aspects of C++11/14/17 and will be able to overcome tasks that are time-consuming or would break your stride while developing.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Uniformly invoking anything callable


Developers, and especially those who implement libraries, sometimes need to invoke a callable object in a uniform manner. This can be a function, a pointer to a function, a pointer to a member function, or a function object. Examples of such cases include std::bind, std::function, std::mem_fn, and std::thread::thread. C++17 defines a standard function called std::invoke() that can invoke any callable object with the provided arguments. This is not intended to replace direct calls to functions or function objects, but it is useful in template metaprogramming for implementing various library functions.

Getting ready

For this recipe, you should be familiar with how to define and use function pointers.

To exemplify how std::invoke() can be used in different contexts, we will use the following function and class:

    int add(int const a, int const b) 
    { 
      return a + b; 
    } 

    struct foo 
    { 
      int x = 0; 

      void increment_by(int const...