Introduction

C++17 adds a few wrapper types that make it possible to write more expressive code. In this chapter, you’ll see std::optional, which models a nullable type. With this utility, your objects can easily express that they don’t have any value. Such behaviour is more straightforward to achieve than using some unique values (like -1, null).

In this chapter, you’ll learn:

• Why we need nullable types
• How does std::optional work and what does it do
• Operations on std::optional
• The performance cost of using the type
• Example use cases

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Let’s get started with the std::optional utility introduced in C++17.