[Issue 3481] PATCH: opPow(), x ^^ y as a power operator

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=3481


Witold Baryluk <baryluk at smp.if.uj.edu.pl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |baryluk at smp.if.uj.edu.pl


--- Comment #15 from Witold Baryluk <baryluk at smp.if.uj.edu.pl> 2009-12-08 21:35:13 PST ---
Just wanted to write: Thanks!

I have about 10 classes with already deffinied opPow just waiting to this for
years.


About Walters question about opPowAssgn, i have few place where i'm for.
example squering in place,  or  (in. for computing exponent of interval
matrix), this isn't actually inplace, but makes code more readble, other i
example in my libraries i see units library, where i see something like this:

    Self opPowAssign(int b) {
        if (b >= 0) {
            nom = pow(cast(int)nom, b);
            denom = pow(cast(int)denom, b);
        } else {
            auto newnom = pow(cast(int)denom, -b);
            denom = pow(cast(int)nom, -b);
            nom = newnom;
        }
        return this;
    }

Clearly first can use opPowAssign, of course in such simple example compiler
should be detect that x = x ^^ y, for simple types can be done in place. And
this opPowAssign is used in few places also.

Or clearly like this:

    Self opPowAssign(int b) {
        nom ^^= b;
        denom  ^^= b;
        if (b < 0) {
            swap(nom, denom);
        }
        return this;
    }


I have also few places with something like:

  new_step = pow(previous_step, f(x))

  it can be changed to: step ^^= f(x). 

and new_step is not nacassarly float or double, it can be slightly more complex
structure like interval vector (and exponentation of it can be done in-place).


I also think that sometimes pepole will have not enaugh operators, and for the
sake of consistency it is good to have opPowAssign. :) Not nacassarly good for
clearity of code if it will use ALL opXAssign for very diferent things.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------