Issue 3789, stucts equality

[Andrej Mitrovic]

On 3/29/12, Andrej Mitrovic <andrej.mitrovich at gmail.com> wrote:
> Speaking of which, does anyone have some sort of template to
> autogenerate an opEquals that compares all fields of a struct via
> '=='?

Well that took 2 seconds.

import std.range;

template safeOpEquals(T)
{
    bool opEquals(T t)
    {
        foreach (lhsField, rhsField; lockstep(this.tupleof, t.tupleof))
        {
            if (lhsField != rhsField)
                return false;
        }

        return true;
    }
}

struct Foo
{
    int[] arr;
    mixin safeOpEquals!Foo;
}

void main()
{
    Foo a, b;
    a.arr = [1, 2, 3].dup;
    b.arr = [1, 2, 3].dup;
    assert(a == b);
}

D makes things so damn easy.