C / C++ / MFC

5-Nov-12 17:33

I've been using the auto keyword, lambdas and move constructors so far and all seems very cool. If the only thing they added was the auto keyword it would still be worth upgrading. This is just awesome...

auto it = someCollection.begin();

...but of course the downside is we now need cbegin() as well

Sarath C5-Nov-12 20:01

Sarath C

5-Nov-12 20:01

This might help in lot of cases, but I really wonder if C++ 11 can reduce the pain of memory mangement. In my experience, auto variables are hardly I needed for my development. but really got tired of several gotchas and memory corruption and management with C++

-Sarath.

My blog - iSpeak code

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Richard MacCutchan5-Nov-12 23:25

5-Nov-12 23:25

_Josh_ wrote:
auto it = someCollection.begin();

[puts on curmudgeonly old git voice] A total abomination which will lead to lazy programmers (as if there weren't enough already), and unreadable code.

One of these days I'm going to think of a really clever signature.

Joe Woodbury6-Nov-12 8:32

Joe Woodbury

6-Nov-12 8:32

Don't get me started. Today's object spaghetti makes the old C spaghetti pale in comparison.

C++11 advocate: Look, I made the code more awesome.
Me: It's slower, more complicated than it needs to be and much harder to find bugs. Why not just use C#?
C++11 advocate: But, it's more awesome!

(I actually heard someone today advocate that all pointers must be wrapped in shared_ptr, no matter what. I'm even working on some code that did that for absolutely no apparent reason--the delete happens within three lines and there is a catch around the call to which the pointer is passed AND the pointer is not actually shared. Yet, they not only used a shared_ptr, but spent time creating a factory to instantiate the only instantiation ever of the object to which the pointer is passed.)

User 5838526-Nov-12 9:50

6-Nov-12 9:50

But the variable is still typed. There is not much in c++ that can't be abused. I think used well auto will make life better.

Richard MacCutchan6-Nov-12 22:27

6-Nov-12 22:27

_Josh_ wrote:
I think used well auto will make life better.

I don't see how writing auto rather than a type will make life better.

One of these days I'm going to think of a really clever signature.

User 5838526-Nov-12 23:09

6-Nov-12 23:09

Just easier. At first I was quite sceptical, anything that looks like it might break c++'s type safety is bound to raise suspicion but after reading and playing with it a bit it's actually harder to shoot yourself in the foot than I'd first thought.

The rvalue references are a much bigger change but we've seen some good performance benifits from that.

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C^hris L^osinger6-Nov-12 3:05

C^hris L^osinger

6-Nov-12 3:05

you've come a long way, "void *"

User 5838526-Nov-12 9:51

6-Nov-12 9:51

Indeed, a var created with auto is typed. void * is still awesome occasionally.

David Crow6-Nov-12 4:00

David Crow

6-Nov-12 4:00

Hasn't auto always been a part of the C language? Maybe it has a new meaning these days?

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Maximilien6-Nov-12 4:24

Maximilien

6-Nov-12 4:24

auto will "automagically" derive the type of the expression.

For normal simple types it does not add much, but more complex types it can make things easier.

C++

auto i = 0; // kind of useless.

C++

std::vector<int>::iterator iterator = myVector.begin();
auto iterator = myVector.begin(); // much usefull, unless you use badly named variables.

It makes things easier when working with lambdas (and I have not use them yet, current project is still VS2008).

Nihil obstat

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C^hris L^osinger6-Nov-12 10:01

C^hris L^osinger

6-Nov-12 10:01

yep, it has a new meaning.

because why clutter the language with a new keyword when you can assign a new meaning to an existing keyword ? efficiency!

Putting a COM dll inside a COM dll

WebMaster5-Nov-12 5:39

WebMaster

5-Nov-12 5:39

Hi,
I am new to C++ but am quite handy with C# and my problem is this. I have a dll (COM) - call it s.dll that wont work properly with VB ( it crashes on events etc) but im informed the dll works fine in a C++ enviroment.
My idea is to write a COM dll in C++ that propogates the methods etc of s.dll and then use this new COM dll in my VB code. I have seen how to write a COM dll and the ATL wizzards using VS6 but I dont know how to add s.dll to my new dll that im writing in VS6.
Can anyone point me to an example of how to add s.dll to COM dll in Vis Studio 6 that uses the ATL?

Thanks,
Andrew

Richard MacCutchan5-Nov-12 6:20

5-Nov-12 6:20

andrewdunbabin wrote:
that wont work properly with VB ( it crashes on events etc) but im informed the dll works fine in a C++ enviroment.

This does not guarantee that there is something inherently wrong with the DLL that can be fixed by putting it inside another DLL. The first thing you should do is try and find out why it is crashing, rather than trying to fix a problem which may not exist.

One of these days I'm going to think of a really clever signature.

WebMaster5-Nov-12 6:47

WebMaster

5-Nov-12 6:47

I have been back to the body that wrote the DLL and they arent interested and I have no idea and no time or inclination to find out why it wont work properly. I am looking for an answer to the question I posed as this is meant to be the idea of this forum is it not?

Andrew

Richard MacCutchan5-Nov-12 6:56

5-Nov-12 6:56

Well, I gave you an idea, it's up to you what to do next.

One of these days I'm going to think of a really clever signature.

Chris Meech5-Nov-12 8:13

Chris Meech

5-Nov-12 8:13

andrewdunbabin wrote:
but I dont know how to add s.dll to my new dll that im writing in VS6

For your new DLL project, you do not need to add s.dll to it. Rather you will need to add headers (s.h) to one of your source files and then when you link your DLL, you will need to include a library file (s.lib) in the libraries list. Do you have those files available to use? Smile | :)

As Richard was mentioning though, it would be a good idea to find out why the crash is occurring in the first place. Without that knowledge, how do you ensure that your DLL project wont have the same issue. Smile | :)

Chris Meech
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client server query

akki2309915-Nov-12 2:35

akki230991

5-Nov-12 2:35

hello!!
how can we send a message from a client to another client in a client server architecture ?
i am trying to implement an algorithm in c++ in which i want to send message from each node to the neighbouring nodes for some reason and to further implementation ..i m confused how to do dis because i have never worked with network programming before in c. i have studied some codes but they are either sending message from server to client or client to server...can someone help please?

Re: client server query

Richard MacCutchan5-Nov-12 4:19