String pointers (using stl) - C / C++ / MFC Discussion Boards

YaronNir1-Sep-03 3:59

1-Sep-03 3:59

hi all,

I know the STL class deque is a sort of a sorted vector.

i have a data class as follows:

class CMyData
{
public:
   CString m_szStr1;
   CString m_szStr2;
}

then i insert this data class to the deque as follows:

m_deque.push_back(pMyData);

what do i need to write to determine the sorting rule??? according to what the deque sorts its elemets???

thanks in advanced

Yaron

Ask not what your application can do for you,
Ask what you can do for your application

Re: STL deque container question

ZoogieZork1-Sep-03 4:20

ZoogieZork

1-Sep-03 4:20

Actually, a std::deque is not like a sorted vector -- it's a vector that has constant time insertion/removal from both ends (instead of just the end). The name "deque" means "double-ended queue".
http://www.sgi.com/tech/stl/Deque.html[^]

If you want a sorted collection, use a std::set.

- Mike

Re: STL deque container question

YaronNir1-Sep-03 4:21

YaronNir

1-Sep-03 4:21

hi,

thanks for the reply, i know understand what you mean....

i can't use set because i can allow duplicated items....what else can u suggest?

thanks again

Yaron

Ask not what your application can do for you,
Ask what you can do for your application

Re: STL deque container question

ZoogieZork1-Sep-03 4:24

ZoogieZork

1-Sep-03 4:24

YaronNir wrote:
i can't use set because i can allow duplicated items

Take a look at std::multiset:
http://www.sgi.com/tech/stl/multiset.html[^]

- Mike

Re: STL deque container question

YaronNir1-Sep-03 4:29

YaronNir

1-Sep-03 4:29

thanks a lot man Smile | :)

that helped me!

Ask not what your application can do for you,
Ask what you can do for your application

Wrapping Popup Menus

Neal Stublen1-Sep-03 3:32

Neal Stublen

1-Sep-03 3:32

Is it possible to easily wrap a popup menu into multiple columns. I would like something like the Start menu on Windows XP, but haven't been able to determine if this is a non-standard menu that Microsoft has implemented. I don't see anything in the SDK documentation to select between scrolling or wrapping popup menus.

Thanks.

Neal Stublen
http://www.awesoftware.com

Re: Wrapping Popup Menus

Neville Franks1-Sep-03 10:49

Neville Franks

1-Sep-03 10:49

You may be able to get somewhere using Owner Draw menus, other than that I think you are on your own.

Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com

String pointers (using stl)

RChin1-Sep-03 2:52

RChin

1-Sep-03 2:52

Now, maybe its because its Monday, or maybe I truely am a dumbass; But I've got a bit of a problem code involving string pointers.

Let me explain: I've got a function that constructs a string and returns:

LPCTSTR CSomeClass::GetSerialString()
{
	std::ostringstream strstream;
	strstream<<	std::setfill((TCHAR)'0')<<\
				std::setw(5)<<m_nSerial;
	strstream<<std::flush;

	//
	// this string should now be 5 characters long.
	ASSERT( (strstream.str()).length() == 5 );	

	return (strstream.str()).c_str(); //<-- contains the correct string characters}
}

Whenever this function is called using the following code:

string strSerial;
strSerial = GetSerialCodeString(); //<-- strSerial is gibberish

The strSerial variable points to an invalid string array, even though at the point of tracing, the GetSerialString function contains the correct string.
Can someone explain why the LPCTSTR return value gets destroyed?

I Dream of Absolute Zero

Re: String pointers (using stl)

Joaquín M López Muñoz1-Sep-03 3:01

Joaquín M López Muñoz

1-Sep-03 3:01

Can someone explain why the LPCTSTR return value gets destroyed?

Because the LPCSTR returned is a pointer to the internal string of strstream, and strstream (and its asocciated string) is destroyed as soon as GetSerialCodeString exits. Use a smarter data type like string itself:

std::string CSomeClass::GetSerialString()
{
  // as before
  return strstream.str();
}
...
string strSerial;
strSerial=GetSerialCodeString();

This ought to work because string has an overloaded copy constructor that takes care of safely moving the internal resources between objects.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: String pointers (using stl)

RChin1-Sep-03 5:58

RChin

1-Sep-03 5:58

cheers dude!

I Dream of Absolute Zero

Icons in the application bar

Piero B1-Sep-03 2:40

Piero B

1-Sep-03 2:40

In the windows right corner there is a set of icons which represents some application running on PC. How can I add a new icon to this set, how can I interact with this one?
Thanks

Telecommunication Engineer.
He works from more than 3 years as a software consultant over distributed systems developed in C++ or Java and based on a CORBA or DCOM tecnology. Knowledge of relationship and object DB

Re: Icons in the application bar

Trollslayer1-Sep-03 4:15

Trollslayer

1-Sep-03 4:15

The area you describe is called the system tray.
There is a sample project by Chris to guide you:
Tray Calendar[^]

Elaine Rose | [Rose]

The tigress is here Big Grin | :-D

Re: Icons in the application bar

Anonymous2-Sep-03 4:27

Anonymous

2-Sep-03 4:27

Thanks

MAPI

ranjjj1-Sep-03 2:09

ranjjj

1-Sep-03 2:09

hello sir
I have written a MAPI client program in C++..
what all softwares do i need to install for this program to run..
is visual studio enough..
or is there anyother simple software for MAPI to get executed??
actually i have to run tihs porgram in a fresh machine..what al softwares do i need for tis C++ MAPI client to run onthe fresh machine??
do i needto install microsoft exchange server too..coz' i remember reading somewhere that
"The information here only applies to MAPI client applications that access Exchange."
what else do i need to install for my program to run??

ranjani

Re: MAPI

Vitali Halershtein1-Sep-03 2:19

Vitali Halershtein

1-Sep-03 2:19

Hi,

You pass mapi questions during last month Smile | :)

To install mapi you need register Msmapi32.ocx using
regsvr32.
In some casees you will need to have file Msmapi.srg with
licenses.

Vitali
http://www.creative-case.com[^]

Re: MAPI

ranjjj1-Sep-03 2:29

ranjjj

1-Sep-03 2:29

what is that msmapi32.ocx ??how do i register into it??

or is the file.. msmapi.srg enough for running my program?

ranjani

Re: MAPI

Vitali Halershtein1-Sep-03 2:35

Vitali Halershtein

1-Sep-03 2:35

1. copy MSMAPI*.* files in the system directory
2. run regsvr32.exe msmapi32.ocx to register

Vitali
http://www.creative-case.com[^]

Re: MAPI

ranjjj1-Sep-03 3:13

ranjjj

1-Sep-03 3:13

do i need MS exchange server to run my client??
or is the file u specified before sufficient for executing it??

ranjani

Re: MAPI

Vitali Halershtein1-Sep-03 3:29

Vitali Halershtein

1-Sep-03 3:29

you may have any email server including 'exchange'.

Vitali
http://www.creative-case.com[^]

Re: MAPI

ranjjj1-Sep-03 3:33

ranjjj

1-Sep-03 3:33

what do u mean by this statement??
can i have more than 1 mail server in my system??
what is ms exchange server??

ranjani

Re: MAPI

ranjjj1-Sep-03 3:36

ranjjj

1-Sep-03 3:36

"The information here only applies to MAPI client applications that access Exchange."
what does the above written statement mean??

ranjani

Re: MAPI

Vitali Halershtein1-Sep-03 4:01

Vitali Halershtein

1-Sep-03 4:01

Fist part of the question: now you know how to install MAPI.
OK?
Second part: you don't need to install exchange server. MAPI can work
with any email server supported it.

I hope clear?

Vitali
http://www.creative-case.com[^]

Re: MAPI

ranjjj1-Sep-03 19:27

ranjjj

1-Sep-03 19:27

so u mean to say..in a fresh machine MAPI won't work just with visual studio installed in it.,is it what u mean??

ranjani

Recursive to iterative.

1-Sep-03 1:53

I don't know why but recursion is always a problem for me. T_T Actually this is my mid-term test and I screw it. Y_Y Anyways, can anyone help me solve this please?

The teacher gave me 3 files for the problem(1 header file and 2 source files.) This is part of them.

/*Change the implementation of 'find' and 'insert' function to use an iterative algorithm instead of resursion.*/

struct cell // cell in a tree
{
keytype key;
valuetype value;
cell *left;
cell *right;
};
typedef cell *cellptr;

cellptr sortset::find(cellptr temproot, keytype key)
{
if (temproot == 0) return 0;
else
{
int compare = keycmp(key, temproot->key);
if (compare == 0) return temproot;
else if (compare < 0)
return find(temproot->left, key);
else
return find(temproot->right, key);
}
}

void sortset::treeinsert(cellptr &temproot, keytype key, valuetype value)
{
if (temproot == 0)
{
temproot = new cell;
temproot->key = key;
temproot->value = value;
temproot->left = temproot->right = 0;
}
else
{
int compare = keycmp(key, temproot->key);
if (compare < 0)
treeinsert(temproot->left, key, value);
else if (compare > 0)
treeinsert(temproot->right, key, value);
}
}

void sortset::insert(keytype key, valuetype value)
{
treeinsert(root, key, value);
}

Thanks in advance Smile | :)

Re: Recursive to iterative.

Joaquín M López Muñoz1-Sep-03 2:50

Joaquín M López Muñoz

1-Sep-03 2:50

This is homework, so it is not fair to provide a full solution. Instead, I can give you some guidance. In a recursive function, each time the function is further invoked a new set of argument and local variables is created. In your particular case, find only uses two argument variables, namely temproot and key. So, you can think of the function in progress as progressively creating variables temproot1, key1, temproot2, key2 and so on. Now, if you want to avoid recursion, you'll have to find a way to reuse the local variables so that they adopt the rol they'd have in a recursive call. find is particularly simple, as key is really a constant value (it never changes inside the function), and as for temproot you can notice that it is no longer used after recursively invoking find, so you can safely change it to hold the value it'd have in the recursive invokation and loop again (instead of calling find.)

Good luck, don't hesitate to post again if you stuck somewhere.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

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