CppCon 2020

In C++, as in many other languages, classes are the key feature that supports data abstraction. A C++ class is essentially a C structure, but with added capabilities that support object-oriented programming as well as better type safety, resource management, and usability.

Although some of these added capabilities require additional storage allocation or run-time support, most do not. Thus, the storage layout for a C++ class can be as simple as the layout for a C structure. Unfortunately, too many programmers imagine that classes incur space and speed penalties that simply aren’t there.

This session offers a practical look “under the hood” to see how compilers typically implement the storage layout and member access for C++ classes. It also explains how compilers typically implement member function calls. You’ll come away with a better sense of what using classes actually costs in speed and space. You’ll gain insights that will help you with a variety of programming tasks, including debugging, performance tuning, and working with objects that have rigid layout requirements.