On 12/30/10 3:36 PM, "Jérôme M. Berger" wrote:
so wrote:
On Thu, 30 Dec 2010 21:15:30 +0200, Jérôme M. Berger<[email protected]>
wrote:
Andrei Alexandrescu wrote:
Many good examples do prove a ton though. Just off the top of my head:
- complex numbers
Multiplication and division are different from each other and from
addition and subtraction.
- checked integers
- checked floating point numbers
- ranged/constrained numbers
More or less the same case, so I'm not sure that they make three.
Other than that agreed.
- big int
- big float
- matrices and vectors
- dimensional analysis (SI units)
- rational numbers
- fixed-point numbers
For all of those, multiplication and division are different from
each other and from addition and subtraction.
So what your examples do is actually prove *Steven's* point: most
of the time, the code is not shared between operators.
Jerome
First, most of these don't even have a division operator defined in math.
?? The only type in this list without a division operator is vector
all the others have it.
Second, you prove Andrei's point, not the other way around, since it
makes the generic case easier, particular case harder.
I'm sorry? What do you call the "generic case" here? All this list
shows is that each operator needs to be implemented individually
anyway. Andrei's point was exactly the reverse: he claims that most
operators can be implemented in groups which clearly isn't the case
here.
And I stand by that claim. One aspect that seems to have been forgotten
is that types usually implement either op= in terms of op or vice versa.
That savings alone is large.
Andrei
