Why does Unconst exist?

[Tejas via Digitalmars-d-learn]

When I initially saw it, I was hopeful that it would allow me to 
bypass some of the restrictions of ```const``` , but it literally 
just takes a type and strips the ```const``` from it, you can't 
pass a variable to it in order to get rid of ```const``` . What 
use does it serve then?

https://dlang.org/library/std/traits/unconst.html