Re: Const Static variables set at run time and a design question.

From:
=?ISO-8859-1?Q?Marcel_M=FCller?= <news.5.maazl@spamgourmet.com>
Newsgroups:
comp.lang.c++
Date:
Tue, 29 Sep 2009 14:49:38 +0200
Message-ID:
<4ac20263$0$31869$9b4e6d93@newsspool3.arcor-online.net>
Hi,

Jim wrote:

I've a set of data which has two spectra associated with each
position. For each spectra you convert from an array position to a
real value using an array offset, a delta and a velocity offset.
These are common to all spectra of the same type and don't change
through the program's run. Unfortunately I don't know them until I
load the file, unless I hard code them and I don't want to do that.


so they are NOT const static because they change while the application runs.

Only solution I can think of is to have a user-defined object called
conversion which has const members set in the constructor and const
accessor methods and have a static object in each type of the specific
spectra classes which inherit from the spectra base class. Does this
seem correct?


Something like that is possible. But I would keep conversion as simple
as possible:

struct conversion
{ double offset;
   double whatever;
};

class SpectraBase
{
   public virtual const conversion& GetConversion() const = 0;
   ...
};

Marcel

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