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digitalmars.D.learn - opDollar()

reply Caligo <iteronvexor gmail.com> writes:
"In the expression a[<expr 1>, ..., <expr k>], if $ occurs in <expr
i>, it is rewritten as a.opDollar!(i)()."  -- TDPL, pg 380

Is that correct? if so, could some one give an example code?  I don't
understand the need for the parameter.

Also, what is the signature for opDollar() in a struct.  I'm getting
errors trying to implement this.
Mar 26 2011
parent reply Dmitry Olshansky <dmitry.olsh gmail.com> writes:
On 26.03.2011 11:03, Caligo wrote:
 "In the expression a[<expr 1>, ...,<expr k>], if $ occurs in<expr
 i>, it is rewritten as a.opDollar!(i)()."  -- TDPL, pg 380

 Is that correct? if so, could some one give an example code?  I don't
 understand the need for the parameter.

 Also, what is the signature for opDollar() in a struct.  I'm getting
 errors trying to implement this.

multidimensional array (e.g. an 2D raster Image) you'd have: img[$-1, $-1] = lastValue; // the first dollar should resolve to "width", the second to "height" Now speaking of it's implementation - it's quite broken. The relevant bug report is http://d.puremagic.com/issues/show_bug.cgi?id=3474 (vote up!) Still it's not considered to be a critical one, since you can workaround it by: img[img.width-1,img.height-1] = lastValue; -- Dmitry Olshansky
Mar 26 2011
parent Don <nospam nospam.com> writes:
Dmitry Olshansky wrote:
 On 26.03.2011 11:03, Caligo wrote:
 "In the expression a[<expr 1>, ...,<expr k>], if $ occurs in<expr
 i>, it is rewritten as a.opDollar!(i)()."  -- TDPL, pg 380

 Is that correct? if so, could some one give an example code?  I don't
 understand the need for the parameter.

 Also, what is the signature for opDollar() in a struct.  I'm getting
 errors trying to implement this.

multidimensional array (e.g. an 2D raster Image) you'd have: img[$-1, $-1] = lastValue; // the first dollar should resolve to "width", the second to "height" Now speaking of it's implementation - it's quite broken.

It's not broken -- it's not implemented at all!
 The relevant bug report is 
 http://d.puremagic.com/issues/show_bug.cgi?id=3474 (vote up!)
 Still it's not considered to be a critical one, since you can workaround 
 it by:
 img[img.width-1,img.height-1] = lastValue;
 

May 02 2011