toml11 | Since toml : : find internally uses toml : : get | Parser library

I am working on a C++ project. It is not much complicated so far, yet depends on a bunch of "popular" libraries (nlohmann/json, ToruNiina/toml11 just to name a few). All of them have some CMakeLists.txt and from my not-that-experienced point of view, I consider them well structured.

Now of course I can compile the libraries one by one, or include a "copy" into my project repo, but I want to be better than that. After researching about available build tools, I have decided to use cmake to build and manage a C++ project. The promise was to get a stable, widely supported tool that will help to simplify & unify the build process. Moreover, from the project nature I have no privilege to impose any requirements on the target machine; I need to pack everything for the deployment.

I have spent several days reading, watching and testing out various cmake tutorials, handbooks and manuals. I have to admit, I quickly started to feel that a tool that is supposed to clarify development process keeps introducing new obscurities contrary to its purpose. Originally, I credited this to my lack of experience, yet...

I read articles about why not to bundle dependencies, only to be followed by methods of doing so. I have found recommendation to use one way A over B, C over B and later A over C. It took me a while to figure out the differences between 2.8 and 3.0, the obscurity of target_link_libraries, setting cxx version and/or compiler warning flags and so on.

My point is that even after an exhausting expedition into the seas of cmake, I am still not sure about some elementary questions:

How is cmake meant to be used?

What is a standard, what is a courtesy, and what is none of those?

How can I tell that something is a feature, an archaic backwards compatibility, or both?

Now I will illustrate this on my project. I only need something like this