You will need a compiler that supports C++ 17; I used GCC 7.4.0c.
The code is on GitHub at https:/​/​github.​com/​PacktPublishing/​Hands-​On-​Functional-Programming-​with-​Cpp in the Chapter16 folder. It includes and uses doctest, which is a single-header open source unit testing library. You can find it in the GitHub repository at https:/​/github.​com/​onqtam/​doctest.