Re: Rebind template(bug?)

[Jack Applegame via Digitalmars-d-learn]

On Monday, 22 August 2016 at 00:43:00 UTC, Engine Machine wrote:
The following code works and does what I want!
template InstantiateOrEmptySeq(alias tmpl, args...)
{
    alias Seq(T...)=T;
    static if (args.length > 0)
        alias InstantiateOrEmptySeq = tmpl!(args[0 .. $-1]);
    else
        alias InstantiateOrEmptySeq = Seq!();
}


class T(A...) : InstantiateOrEmptySeq!(T, A)
{       
        static if (A.length == 0)
        {
                // Base class
                int x;
        } else  
        static if (A[$-1] == "Animal")
        {
                int y;
        } else
        static if (A[$-1] == "Dog")
        {
                int z;
        } else
        static if (A[$-1] == "Pug")
        {
                int s;
	} else static assert(A[$-1]~" not a defined class of 
"~this.stringof);
}

Why don't you like a cleaner (in my opinion) solution?

class T() {
        // Base class
        int x;
}

class T(A...) : T!(A[0..$-1]) { 
        static if (A[$-1] == "Animal")
        {
                int y;
        } else
        static if (A[$-1] == "Dog")
        {
                int z;
        } else
        static if (A[$-1] == "Pug")
        {
                int s;
	} else static assert(A[$-1]~" not a defined class of 
"~this.stringof);
}