Modern C++ Programming Cookbook

Getting ready

For this recipe, you should be familiar with the std::variant type. It is recommended that you first read the previous recipe, Using std::variant as a type-safe union.

To explain how variant visitation can be done, we will consider a variant for representing a media DVD. Let's suppose we want to model a store or library that has DVDs that could contain either music, a movie, or software. However, these options are not modeled as a hierarchy with common data and virtual functions, but rather as non-related types that may have similar properties, such as a title. For simplicity, we consider the following properties:

• For a movie: Title and length (in minutes)
• For an album: Title, artist name, and a list of tracks (each track having ...