Am I getting this all right?

[Jarrett Billingsley]

"Jason House" <jhouse at mitre.org> wrote in message 
news:elsctg$5ca$1 at digitaldaemon.com...
> An earlier post showed stack with push and pop for an array.  How does one 
> do a
> queue? a set?

You could also use an associative array to model a set.

bool[int] set;
set[4] = true;
set[6] = true;
set[10] = true;

if(4 in set)
    writefln("4 is in the set");

foreach(v, nothing; set)
    writefln(v);

set.remove(6);

The "nothing" in the foreach loop is because the values in the associative 
array are useless -- they're just there because they have to be.

In fact, why don't I just make a little set class to make it a little 
prettier.

class Set(T)
{
    protected bool[T] mData;

    public this()
    {

    }

    public void add(T value)
    {
        mData[value] = true;
    }

    public bool opIn_r(T value)
    {
        return ((value in mData) !is null);
    }

    public int opApply(int delegate(inout T value) dg)
    {
        int result = 0;

        foreach(value, n; mData)
        {
            result = dg(value);

            if(result)
                break;
        }

        return result;
    }

    public void remove(T value)
    {
        mData.remove(value);
    }
}

void main()
{
    auto scope set = new Set!(int);

    set.add(4);
    set.add(6);
    set.add(10);

    if(4 in set)
        writefln("4 is in the set");

    foreach(v; set)
        writefln(v);

    set.remove(6);
}