Re: Reinitialize Structure Object
* Mike Copeland, on 19.06.2010 20:18:
* Mike Copeland, on 19.06.2010 15:07:
How can I reinitialize all the values in the structure object below?
You can't reinitialise anything. You can initialise it or you can
assign to it.
This structure object (myTest) is common to several subprograms in a
larger program, and when I engage any of the subprograms I want to
assure that the structure is (re)initialized to the zero value I've
defined in its declaration.
Huh? What do you mean? Assign an empty struct to it
void foo(TestStructure&rTest) {
...
rTest = TestStructure();
...
Not sure that can work, as several different subprograms need to
access the same data throughout their processing. I require that the
structure object be global data (I know, that's frowned upon, but that's
how I do it...), so passing referencing and having instantiated
object(s) doesn't do what I want.
I'm just looking for a simple way to clear a structure (of common
counters) each time I engage various functions in a menu-driven program.
Sloppy and somewhat kludgey, but that's how it is... 8<{{
Do you have a C++ compiler?
Yes, VS6.0 How does that help in this question?
How can a C++ compiler help you determine whether something works?
I assume you mean that I should use it to develop and try test cases,
right?
That too.
And in your case, with large existing code base that seems to be tied to a very
old pre-standard compiler, having reproducible tests is very important.
But I was thinking primarily of just testing Victor's advice, which you
expressed some doubts about ("not sure that can work").
Indeed it works with a modern compiler:
TestStructure myGlobal;
void foo()
{
// "Reinitialize" myGlobal:
myGlobal = TestStructure();
}
It's that simple.
But MSVC 6.0 just may suprise you by doing the wrong thing (if it does it will
always do), and so testing is a good idea.
[snip]
And part of my difficulty is that I am a very old programmer (70)
who's been programming for 50 years - it's hard adapting to new concepts
(OOP, etc.) and styles. 8<{{
To quote myself about what OOP is:
Instead of common functions that have knowledge of all relevant types of
objects, use objects that have knowledge of all relevant type-specific
functions.
That's it.
But as with a simple-minded little creature that follows a fixed very simple
algorithm for avoiding obstacles (e.g., collision? back off two steps and turn
right), and that is placed on a field with stones and trees and stuff, the
result of applying OOP to a complicated real problem can seem to be pretty
complex. On the bright side, though, the whole point is that it will be less
complex and easier to maintain than a non-OOP solution. Because it centralizes
knowledge, i.e., it reduces redundancy, which is a main cause of complexity.
PS: You will find it beneficial to upgrade to a more modern compiler. They're free.
So I hear...my reluctance to do so is based on a fear of conversion
efforts (I have over a million lines of legacy code and libraries) - I
don't know what would be the most practical switch to make (VS8, VS10)
and which wouldn't impose any significant environment changes (.NET
requirements, distribution issues, etc.) on me and my client.
Your fear is well-founded: it is a non-trivial task to convert such code.
Hence, you're not alone in being stuck with an old compiler!
I think I would attack such a problem by using both the old and new compiler,
the old one for yet-to-be-converted libraries, and the new one for initially
just a dummy 'main' and then for more and more. However, I'd try that out on
something made-up and much smaller first, just to be sure the approach is valid.
And as you can infer from that "I think" that I haven't done such a large scale
conversion, so it's purely my initial thoughts. E.g., I'm pretty sure that it's
impractical to automate very much of it, although that approach can work for
some other languages like Python 2.x -> 3.x conversion. So I'd go for the
gradual one-library-manually-at-a-time approach.
To date,
I haven't found any compelling reasons - such as stuff that doesn't work
or performance issues - which force me to upgrade.
Being able to use modern libraries such as Boost is pretty compelling... ;-)
Cheers & hth.,
- Alf
--
blog at <url: http://alfps.wordpress.com>