import std;

​

// Unlike sequences, tuples don't auto-expand

template AliasTuple(seq...)

{

    alias expand = seq;

    enum length = seq.length;

}

​

// Some sample data 

alias s0 = AliasTuple!();

alias s1 = AliasTuple!(1);

alias s2 = AliasTuple!(1, 2);

alias s3 = AliasTuple!(1, 2, 3);

alias s7 = AliasTuple!(1, 2, 3, 4, 5, 6, 7);

​

/// Removes the element at index `idx` from the given sequence `seq`.

template removeFromSeqAt(size_t idx, seq...)

{

    static if (seq.length > 0 && idx < seq.length)

        alias removeFromSeqAt = AliasSeq!(seq[0 .. idx], seq[idx + 1 .. $]);

    else

        static assert (0);

}

​

//pragma (msg, removeFromSeqAt!(0, s0.expand)); doesn't compile - as expected

​

static foreach (s; AliasSeq!(s1, s2, s3, s7))

{

    static foreach (i; 0 .. s.length)

        pragma (msg, "Remove at ", i, " from: ", s.expand, " -> ",  removeFromSeqAt!(i, s.expand));

    pragma (msg, "---");

}

​

void main() {}