Drop
The Drop trait only has one method: drop, which is called automatically
when an object goes out of scope. The main use of the Drop trait is to free the
resources that the implementor instance owns.
Box, Vec, String, File, and Process are some examples of types that
implement the Drop trait to free resources. The Drop trait can also be
manually implemented for any custom data type.
The following example adds a print to console to the drop function to announce
when it is called.
For a more practical example, here's how the Drop trait can be used to automatically
clean up temporary files when they're no longer needed: