newbie prob: referenced parameter only partially changed

[J D]

torhu Wrote:

> J D wrote:
> > Love the language, from the description.  My first day trying to program in D.
> > 
> 
> Nice to hear that.  Here's a page that I found very useful when learning D:
> http://www.prowiki.org/wiki4d/wiki.cgi?LanguageSpecification/KeywordIndex
> 
> > I pass a dynamic char array to a function.  I modify the contents and set the .length to a smaller value (confirmed from within the routine).  When I return the array I passed in has the contents changed, but the length has not changed.  This seems inconsistent to me.
> 
> The array reference consists of the length, and a pointer to the data. 
> What you get inside the function is just a copy of this reference, in 
> other words a different reference to the same data.  Most of the time 
> it's ok to just return a new reference if the function might change it.

I'll have to remember that, but it stil seems a wee bit inconsistent in that it changes the contents but not the length.

> > 
> > I tried putting 'ref' before the 'char []' in the function declaration, but I got a bunch of errors,although the docs said arrays are passed by reference by default.  Can anyone help?
> 
> This should work.  'ref' was added not long ago, so maybe you compiler 
> is too old.  Try using 'inout' instead, which is an older alias for ref.

I am using gdc, and 'inout' worked so I guess it is not the newest.

I tried installing dmd too.  Which is better?  What are the trade-offs?

dmd would not compile the sample code.  It complained of not being able to find libraries even though it was there.

Thanks much for the help.  I have a feeling you'll be hearing more from me.  :)