Is this explanation on Nim manual not good enough to stop people using `cast`
for `ref`, `string` or `seq` type variables?
https://nim-lang.org/docs/manual.html#statements-and-expressions-type-casts
> Type casts are a crude mechanism to interpret the bit pattern of an expression
as if it would be of another type. Type casts are only needed for low-level
programming and are inherently unsafe.

`ref` is actually a pointer and managed by Nim.
Bit copying `ref` can destroys Nim's memory management.
`string` and `seq` are objects containing a pointer to heap managed by Nim.
Bit copying them can destroys Nim's memory management.