I have written a calculator in Rust and libcosmic, the design is copied from gnome-calculator; I discovered 2 things:

  1. I don’t like working on UIs.
  2. I have no idea how to transform

cosmic::widget::button::Builder

to

cosmic::widget::Button;

this code would be so much cleaner if I could return a button::standard() from a function.

The source code.