Set#eql?

static VALUE
set_i_eq(VALUE set, VALUE other)
{
    if (!rb_obj_is_kind_of(other, rb_cSet)) return Qfalse;
    if (set == other) return Qtrue;

    set_table *stable = RSET_TABLE(set);
    set_table *otable = RSET_TABLE(other);
    size_t ssize = set_table_size(stable);
    size_t osize = set_table_size(otable);

    if (ssize != osize) return Qfalse;
    if (ssize == 0 && osize == 0) return Qtrue;
    if (stable->type != otable->type) return Qfalse;

    struct set_equal_data data;
    data.set = other;
    return rb_exec_recursive_paired(set_recursive_eql, set, other, (VALUE)&data);
}