From: Tanton Gibbs (thgibbs_at_[hidden])
Date: 2002-12-11 16:17:30
> optional<int> a();
> optional<int> b();
> optional<int> c(1);
> optional<int> d(2);
> optional<int> e(2);
>
> assert(a == b); // both uninitialized
> assert(a != c); // one uninitialized
> assert(c != d); // both initialized to different values
> assert(d == 3); // both initialized to same value
>
> However, not all types wrapped in optional<T> will be comparable... so,
> I'm not adverse to leaving comparison operators out just to simplify the
> interface. I just don't agree with the current rationale.
>
> William E. Kempf
I assume you mean
assert( d == optional<>(2) );
However, I still think this is incorrect....consider
char c = 'c', d = 'c';
char *p, *q;
p = &c; q = &d;
assert( p != q );
It doesn't matter what their values are...it is the addresses of those
values that matter.
Therefore, I think that, if optional<> is a smart ptr,
assert( d != optional<>(2) );
must be true. Only if two elements are uninitialized should they be
equal...otherwise, we must compare their "pointer" values, not their element
values.
Tanton