Re: Has someone encountered similar issues with -cov?

[Johan Engelen via Digitalmars-d]

On Saturday, 2 July 2016 at 12:26:34 UTC, Andrei Alexandrescu 
wrote:

How would you reshape this?

Maybe:

U opCast(U, T)(T payload)
{
    import std.traits;

    enum descriptiveName = !isUnsigned!T && isUnsigned!U && 
T.sizeof <= U.sizeof;
    enum unsT_sigU = isUnsigned!T && !isUnsigned!U;
    static if (unsT_sigU)
    {
        static assert(U.sizeof <= T.sizeof);
    }

    if (!descriptiveName || payload >= 0)
    {
        auto result = cast(U) payload;
        if (result == payload)
        {
            if (!unsT_sigU || result >= 0)
            {
                return result;
            }
        }
    }

    return hook!U(payload);
}