Why does this not compile?

[Diego]

On Tuesday, 6 March 2018 at 10:03:54 UTC, Shachar Shemesh wrote:
> void main() {
>     struct S {
>         uint value;
>
>         ~this() {
>         }
>     }
>
>     const S a = S(12);
>     S b = a;
> }
>

You cannot assign a const element (`a`) to a non-const element 
(`b`) in `S b = a` expression. To make de assignment, you have to 
cast a to a non-constant expression:

S b = cast(S)a;

Or make `b` as const:

const S b = a;

Or, better, use auto keyword:

auto b = a;