Truly algebraic Variant and Nullable

[ag0aep6g]

On Tuesday, 22 December 2020 at 16:53:11 UTC, jmh530 wrote:
> For
> v = cast(size_t) x;
> I thought @safe prevented explicitly casting an immutable to a 
> mutable, but the code below seems to suggest it is ok in this 
> case...
>
> void main() @safe
> {
>     immutable x = 32;
>     auto v = cast(size_t) x;
> }

It's ok because you're making a copy. Casting from immutable to 
mutable is only dangerous when altering the mutable thing would 
affect the immutable thing, as it happens with pointers and such.