To build any project, we should start with a clear understanding of what logical targets are going to be created in it. In this case, we'll follow the structure shown in the following figure:

Let's explore the structure by following the build order. First, we'll compile calc_obj, which is an object library. We did mention object libraries a few times in the course, but we didn't actually introduce them as a concept. Let's do this now.

Object libraries

Object libraries are used to group multiple source files under a single logical target and are compiled into the (.o) object files during a build. To create an object library, we use the same method as with other libraries with the OBJECT keyword:

Introduction to the Course

First Steps with CMake

The CMake Language

Setting Up Our First CMake Project

Working with Targets

Compiling C++ Sources with CMake

Linking with CMake

Modern CMake for C++ Exam 1

Managing Dependencies with CMake

Testing Frameworks

Program Analysis Tools

Generating Documentation

Installing and Packaging

Creating Our Professional Project

Conclusion

Appendix

Project Layout

Object libraries