Re: Equates or Synonyms?

From:
Stuart Redmann <DerTopper@web.de>
Newsgroups:
comp.lang.c++
Date:
Mon, 28 Nov 2011 02:38:37 -0800 (PST)
Message-ID:
<b3e0b2f6-e058-43eb-b51b-ec238e03f05d@n35g2000yqf.googlegroups.com>
Mike Copeland wrote:

capability to "equate" or use a synonym for
an identifier?


Alf P. Steinbach wrote:

Yes, but it depends on the kind of identifier.
References work for v


On 28 Nov., Mike Copeland wrote:

  ^^^^^^^^^^^^^^^^^^^^^
   I don't understand what you mean here.


He means something like this:
struct DEF_STRUCT
{
  int EPace;
  int& ABetterNameForEPace;
  /* snip */

  // This constructor for DEF_STRUCT binds
  // ABetterNameForEPace to EPace.
  DEF_STRUCT ()
    : ABetterNameForEPace (EPace)
  {}
};

Then you can do:

DEF_STRUCT s;
s.EPace = 5;
std::cout << s.ABetterNameForEPace << std::endl;
s.EPace = 7;
std::cout << s.ABetterNameForEPace << std::endl;

and you'll get the output
5
7

Note that introducing references may alter the binary layout of your
struct. Most probably the reference will be implemented through an
additional pointer.

There is a non-portable compiler extension for Microsoft Visual C++
which lets you achieve the same thing but without any changes to the
binary layout. Google for __declspec property.

However, the simplest would be to just add a setter and getter method
to the struct:
struct DEF_STRUCT
{
  int EPace;
  int getABetterNameForEPace ()
  {
    return EPace;
  }
  void setABetterNameForEPace (int NewValue)
  {
    EPace = NewValue;
  }
  /* snip */
};

Regards,
Stuart

PS: Please keep the names of the people you are quoting from. Better
yet, keep a complete history of the talk (at least the part that you
are refering to). Not everybody has access to all postings of this
group.

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