Re: Error using `equal` with various string types

[Andrej Mitrovic]

On 2/24/13, Jonathan M Davis <jmdavisp...@gmx.com> wrote:
> Those _do_ work. The problem is that you're not trying that; you're trying
> ["foo"].equal(["foo"d]);

Ah that makes sense, thanks.

A run of the mill implementation takes care of things:

bool equal(Range1, Range2)(Range1 r1, Range2 r2)
    if (isInputRange!Range1 && isInputRange!Range2
        && isInputRange!(ElementType!Range1)
        && isInputRange!(ElementType!Range2))
{
    if (r1.length != r2.length) return false;

    foreach (lhs, rhs; zip(r1, r2))
    {
        if (!.equal(lhs, rhs))
            return false;
    }

    return true;
}

It's not tested though, but I see what you mean by recursion now. I'll
file an enhancement.

One thing I don't understand is why the above won't work if I put it
in my own module (compile-time error), it has to be put in
std.algorithm for all the template overloads to be part of one
overload set. Using aliases won't work either, e.g.:

import std.algorithm;

alias std.algorithm.equal equal;  // conflict

bool equal(Range1, Range2)(Range1 r1, Range2 r2)
    if (isInputRange!Range1 && isInputRange!Range2
        && isInputRange!(ElementType!Range1)
        && isInputRange!(ElementType!Range2))
{
    if (r1.length != r2.length) return false;

    foreach (lhs, rhs; zip(r1, r2))
    {
        if (!.equal(lhs, rhs))
            return false;
    }

    return true;
}

It sounds to me like it's a compiler bug.