Arcane Jill wrote:
> Well, now we have opPos() to complement opNeg(). We can overload the unary plus
> operator.
> 
> The obvious implementation is:
> 
> #    T opPos() { return this; }
> 
> (or .dup, or similar). But such trivial functions do seem a little pointless.
> What /else/ could we do with opPlus()? 

char[] opPos() { return "The glass is half full" };

In article <opsbxhk9m95a2sq9@digitalmars.com>, Regan Heath says...
>
>Sorry for being serious'n'all but aren't opPos and opNeg perfectly useful if you're implementing something that can be positive or negative?
>
>Like your Int class Jill?
>
>eg.
>
>class SimpleInt {
>   int value;
>   SimpleInt opPos() { if (value < 0) value = -value; return this; }
>   SimpleInt opNeg() { if (value > 0) value = -value; return this; }
>}
>
>or am I missing something?

Clearly. (Sorry).

I'd want x = -y; to assign x with minus y, not with -abs(y). If y is -3 then the
statement x = -y; should (and will) result in (x == 3). And there is no way I'm
going to change that.

Int does provide the function abs().

In math, the main use for unary plus is to turn a double-valued result into a single-valued result. For instance sqrt(2) is double-valued, but +sqrt(2) is single-valued. It's hard to see how that could be useful in D.

Jill

In article <cecmgc$26dk$1@digitaldaemon.com>, Andy Friesen says...
>
>The most obvious thing in the world:
>
>     void opPos() { this += 0.5; }
>

LOL. Excellent!
Jill

"Arcane Jill" <Arcane_member@pathlink.com> skrev i en meddelelse news:ceamke$1bfo$1@digitaldaemon.com...
> Well, now we have opPos() to complement opNeg(). We can overload the unary
plus
> operator.
> (or .dup, or similar). But such trivial functions do seem a little
pointless.
> What /else/ could we do with opPlus()?
> This is a non-serious thread, so humorous replies are welcome!

It is an obvious candidate for hiding easter eggs in libraries.

Regards,
Martin M. Pedersen

Arcane Jill wrote:

>Well, now we have opPos() to complement opNeg(). We can overload the unary plus
>operator.
>
>The obvious implementation is:
>
>#    T opPos() { return this; }
>
>(or .dup, or similar). But such trivial functions do seem a little pointless.
>What /else/ could we do with opPlus()? 
>
>This is a non-serious thread, so humorous replies are welcome!
>Jill
>
By "fun" I guess you mean something evil like:

struct Test
{
    Test opPos()
    {
       printf("+\n");
       return *this;
   }
      Test opNeg()
    {
       printf("-\n");
       return *this;
   }   }

void main()
{
   Test t;
   + - + + +t;
}

I guess it could have all kinds of evil-non-mathematical uses. 


-- 
-Anderson: http://badmama.com.au/~anderson/

"Arcane Jill" <Arcane_member@pathlink.com> escribió en el mensaje
news:ceamke$1bfo$1@digitaldaemon.com
| Well, now we have opPos() to complement opNeg(). We can overload the unary
plus
| operator.
|
| The obvious implementation is:
|
| #    T opPos() { return this; }
|
| (or .dup, or similar). But such trivial functions do seem a little pointless.
| What /else/ could we do with opPlus()?
|
| This is a non-serious thread, so humorous replies are welcome!
| Jill

Why is it opPos? Shouldn't it be opUnaryPlus, or even opPlus?

-----------------------
Carlos Santander Bernal

Carlos Santander B. wrote:

>"Arcane Jill" <Arcane_member@pathlink.com> escribió en el mensaje
>news:ceamke$1bfo$1@digitaldaemon.com
>| Well, now we have opPos() to complement opNeg(). We can overload the unary
>plus
>| operator.
>|
>| The obvious implementation is:
>|
>| #    T opPos() { return this; }
>|
>| (or .dup, or similar). But such trivial functions do seem a little pointless.
>| What /else/ could we do with opPlus()?
>|
>| This is a non-serious thread, so humorous replies are welcome!
>| Jill
>
>Why is it opPos? Shouldn't it be opUnaryPlus, or even opPlus?
>
>-----------------------
>Carlos Santander Bernal
>
>  
>
opPlus implies that we are adding something.  opPos means positive like opNeg means negative.

-- 
-Anderson: http://badmama.com.au/~anderson/

"J Anderson" <REMOVEanderson@badmama.com.au> escribió en el mensaje
news:cegcuo$13du$1@digitaldaemon.com
| Carlos Santander B. wrote:
|| Why is it opPos? Shouldn't it be opUnaryPlus, or even opPlus?
||
|| -----------------------
|| Carlos Santander Bernal
||
||
||
| opPlus implies that we are adding something.  opPos means positive like
| opNeg means negative.
|
| --
| -Anderson: http://badmama.com.au/~anderson/

But as Jill already pointed: +x = x, -x = -abs(x). (mathematically speaking), so
it's not positive: it's the same

-----------------------
Carlos Santander Bernal

Carlos Santander B. wrote:

> But as Jill already pointed: +x = x, -x = -abs(x). (mathematically speaking), so
> it's not positive: it's the same

It's not true that -x = -abs(x).

If x = -5, then -x = 5, but -abs(x) = -5.

WHAT AN IMPORTANT RESULT! ;)

James McComb

"James McComb" <alan@jamesmccomb.id.au> escribió en el mensaje
news:cehlgr$1ju0$1@digitaldaemon.com
| It's not true that -x = -abs(x).
|
| If x = -5, then -x = 5, but -abs(x) = -5.
|
| WHAT AN IMPORTANT RESULT! ;)
|
| James McComb

(where do I hide, where do I hide????)
Yes, sorry, my mistake. But I still think opPos is not the right name, for the
same reason that +x != abs(x). But I won't argue for that anymore.
(and to think that until a couple of years ago I was a very good
mathemathician...)

-----------------------
Carlos Santander Bernal