Nooo unsigned integers suck, if you subtract 5 from 3 what would you get? Then I had a stroke of genius and figured it out, I have no idea what I'm doing.
That looks like a cool tool (would be cooler if it didn't start freezing up after 15 seconds). But I have a complaint, how is Bill Nye on the same tree as Richard Feynman?
Yeah as others mentioned this is between C and C++, arguably taking best of each language. But indeed this library is based around the idea of having performant UI (as they mostly redraw whole screen on each frame, it has to be quite quick, though there are ways not to do this, this is the most basic case) and generic containers do not really cut it, also usage of exceptions is sort of impossible with the way you have to structure ImGui code. So it's more of a codebase that illustrates how to write performant code, not so much modern C++ guideline.