Have you considered making these work, instead of throwing an exception?

    import std.typecons;

    alias T = Nullable!(int, -1);

    void main()
    {
        T a;
        T b;
        assert(a == b);

        T c;
        T d = 42;
        assert(c != d);
    }

It could be a template parameter for Nullable, and the default be to preserve the current behavior.

On Wednesday, 30 March 2016 at 12:06:24 UTC, Luís Marques wrote:
> Have you considered making these work, instead of throwing an exception?
>
>     import std.typecons;
>
>     alias T = Nullable!(int, -1);
>
>     void main()
>     {
>         T a;
>         T b;
>         assert(a == b);
>
>         T c;
>         T d = 42;
>         assert(c != d);
>     }
>
> It could be a template parameter for Nullable, and the default be to preserve the current behavior.

https://issues.dlang.org/show_bug.cgi?id=14804

A link to the PR is in the last update to this bug.