Embracing (and also Destroying) Variant Types Safely

Designing and implementing a variant type (such as std::variant itself) in C++, at first, seems a rather inane topic. It turns out, however, that a variant type's performance or lack thereof, can have an inordinately large impact on software that directly impacts the bottom-line performance of important applications, such as interpreters. database clients, and communication protocols.

In this talk we will delve into the gory details of designing and implementing variant types, with an emphasis on layout, construction, and destruction. Along the way we'll figure out how to optimize not only the run time of the produced program, but also the time and memory consumed during compilation. These aspects, although seldom discussed, are important for provisioning and deploying continuous integration systems.