Hi, Two years ago, I have created a library who handle metrics type (distance, speed, flow rate, ...). I have simply applied the principle of chrono library (std:: one from clang in my case) and have applied it to other types. I have decided some weeks ago to make it public on github. This project also manage inter-type conversion(speed to distance, or volume to flow rate for example). Before going much further in this project, I would like to get your though about it. Maybe some of you already have had a similar idea, maybe even in a more advanced state, or with another principle of conversion between types? Here is the project link: https://github.com/xtofpic/metrics if you are interested. In this case, don't blame me for the state of the code actually, I know it still need a huge works to do on testing and code reducing by better c++ templates. But if you can just let me know what you think of the idea? And if there is an opportunity to eventually integrate this project into boost afterwards? Best regards, Christophe Pijcke.