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You are great on the giving of advice, but very poor on the testing of your own advice, because if you had tested the advice you were giving, you would have discovered they DON'T WORK. I know they don't work because I applied what you suggested and ended up (the latest) with 6 errors!!
Moreover, if you had looked closely, you would have seen that I had:
typedef pair<string, string> PAIR_KV; That's my "value_type" for the map that you keep talking about so much. It's there! SEE! It's there! I don't need your "MapStr::value_type&" suggestion, but I used it anyway just to see if it would work, ... and IT DIDN'T!! So much for your well-informed advice.
Yes, I had tried removing "const" from all the places they were being used and ended up with errors of one kind or another, and even tried using the reference straight from the parameter list of the function object "operator()" (without creating one on the stack). That didn't work either (meaning, it produced several errors)!
If you had done the various testings as I did, you would have found that "for_each" is just not a good algorithm for dealing with maps. It's obvious you didn't know that, based on the incorrect advice you have been giving.
NONE of the advice you have given so far worked. NONE! But there you are, telling me to go read up on certain STL books. FYI, I do my share of reading, and practicing with the STL almost every day. I certainly DON'T NEED another one of your gratuitous advice. KISS OFF!!
William
Fortes in fide et opere!
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#include <map>
#include <iostream>
#include <utility>
#include <algorithm>
typedef std::map<int, int> IntMap;
struct addone {
void operator()(IntMap::value_type& v) const {
v.second++;
}
};
struct print {
void operator()(IntMap::value_type& v) const {
std::cout << "first = " << v.first << ", second = " << v.second << std::endl;
}
};
int main(int argc, char* argv[])
{
IntMap map;
map.insert(std::make_pair(1, 1));
map.insert(std::make_pair(2, 2));
map.insert(std::make_pair(3, 3));
map.insert(std::make_pair(4, 4));
map.insert(std::make_pair(5, 5));
std::for_each(map.begin(), map.end(), print());
std::for_each(map.begin(), map.end(), addone());
std::for_each(map.begin(), map.end(), print());
return 0;
} I'm just being honest; Do yourself a favor - stop whining and pick up an STL book.
--
You copy and paste yourself into my brain.
You always find your way back into my brain.
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KISS OFF!!
Who needs your crappy little "int" addone sample?
I've had enough of your unworkable samples in the past. I don't need anymore.
If you didn't understand my last message, it states, "I do my share of reading just about everyday." I DON'T NEED you to tell me what to do.
Take your crappy little "map.insert" sample and SHOVE IT!!
It wouldn't hurt for you to do some reading of your own also. You clearly need it. All those unworkable advice you've been giving. You definitely need to do a lot of reading yourself.
William
Fortes in fide et opere!
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At least you're entertaining. 
--
You copy and paste yourself into my brain.
You always find your way back into my brain.
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Even that you lack.
William
Fortes in fide et opere!
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Oh, please guys, continue fighting. This is very funny 
"semper aliquid haeret", Bacon.
-- Sebastián.
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Hey, I'm not fighting.
--
You're entertaining at least.
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<br />
#include <map><br />
#include <iostream><br />
#include <utility><br />
#include <algorithm><br />
#include <string><br />
<br />
<br />
typedef std::map<std::string,std::string> StringMap;<br />
<br />
struct update<br />
{<br />
void operator() ( StringMap::value_type& v ) const<br />
{<br />
if ( v.first == "second" )<br />
v.second = "replaced value";<br />
}<br />
};<br />
<br />
struct print<br />
{<br />
void operator() ( StringMap::value_type& v ) const<br />
{<br />
std::cout << "first = " << v.first << ", second = " << v.second << std::endl;<br />
}<br />
};<br />
<br />
int main( int argc, char* argv[] )<br />
{<br />
StringMap testMap;<br />
<br />
testMap.insert( StringMap::value_type("first", "1") );<br />
testMap.insert( StringMap::value_type("second", "2") );<br />
testMap.insert( StringMap::value_type("third", "3") );<br />
testMap.insert( StringMap::value_type("fourth", "4") );<br />
testMap.insert( StringMap::value_type("fifth", "5") );<br />
<br />
std::for_each(testMap.begin(), testMap.end(), print());<br />
std::for_each(testMap.begin(), testMap.end(), update());<br />
std::for_each(testMap.begin(), testMap.end(), print());<br />
<br />
return 0;<br />
}<br />
However, as you know (from your comments in your original post), the code in the "update" functor is basically doing a find. However, since the for_each does a loop through all elements of the map, this is much less efficient than doing an actual find. If you need to do single updates to elements in a map which have particular key values, it would normally be better to just do the find and then update the element. The for_each algorithm is really only appropriate if you need to access every element in the container.
Best regards,
John
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Thanks for replying.
Your sample does work.
William
Fortes in fide et opere!
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jbarton wrote:
If you need to do single updates to elements in a map which have particular key values, it would normally be better to just do the find and then update the element.
That depends a little on how many values you are updating. If you are updating few elements, then the approach you mention is more efficient. But if the number of values are many, then an iteration is faster. Assuming that the map is implemented as a balanced search tree, you need to find out how O(k * log(n)) relates to O(n), where k is the number of values to update, and n is the number of elements in the map. Of course, if it's a hashmap, then the approach you mention is most likely faster for basically all k (unless, of course, the hash algorithm is very slow).
I guess it would be advantageous to encapsulate this algorithm into its own function, and let itself adapt to the problem size automatically. But hey, how would I know? I just post faulty samples and is a retard according to some.
--
You're entertaining at least.
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I think the idea of iterating through the map to update multiple elements has merit. If (for instance) I want to update the data associated with all keys that match a particular pattern, there really isn't any way that I could do it without iterating through all elements in the map.
When I have a list of specific key values whose data I want to update, I find it difficult to set up a functor that efficiently checks for these key values and then updates the associated data values. It may be possible using another map or hash within the functor to lookup the key value and then get the replacement value. With only simple if / else if comparisons, I think that the overhead of the functor would probably remove any advantage gained by not using find on each key value.
Unless the program I was writing was running too slowly and by profiling I found it to be due to using find to update the map, I would probably stick with using find.
If you know of a better way of writing this functor, let me know. I am always interested in hearing other approaches.
Best regards,
John
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Hello,
please tell me how to make a 2d and 3d vector using stl....and also how to assign and get values from it then.....i think i have made the 2d vector correctly but cant seem to assign values to it..THIS IS THE APPROACH I USED
typedef std::vector<int> sArray;
std::vector<sarray> m_map;
std::vector<int> v;
v.resize(m_no_horz_tiles,-1);
for (int i = 0 ; i < m_no_vert_tiles; i++)
{
m_map.push_back(v);
}
but the thing is i cant assign values to my 2d vector like this, given i and j
m_map[i][j] = 1; //value not stored don know why  ?????
please guide me...
Thank you
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Interesting.
Try initializing it via constructor.
std::vector v(m_no_horz_tiles, 0);
Kuphryn
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Hello Omar,
I rewrote your code above as follows :
#include <vector>
#include <iostream.h>
#include <stdio.h>
typedef std::vector<int> sArray;
void main()
{
std::vector<sArray> m_map;
std::vector<int> v;
int i = 0, j = 0, m_no_horz_tiles = 5, m_no_vert_tiles = 10;
v.resize(m_no_vert_tiles, 0);
for (i = 0 ; i < m_no_horz_tiles; i++)
{
m_map.push_back(v);
}
for (i = 0 ; i < m_no_horz_tiles; i++)
{
for (j = 0 ; j < m_no_vert_tiles; j++)
{
m_map[i][j] = (i * 10) + j;
}
}
for (i = 0 ; i < m_no_horz_tiles; i++)
{
for (j = 0 ; j < m_no_vert_tiles; j++)
{
cout << "m_map[" << i << "][" << j << "] == " << m_map[i][j] << endl;
}
}
}
The above code yielded the following output :
m_map[0][0] == 0
m_map[0][1] == 1
m_map[0][2] == 2
m_map[0][3] == 3
m_map[0][4] == 4
m_map[0][5] == 5
m_map[0][6] == 6
m_map[0][7] == 7
m_map[0][8] == 8
m_map[0][9] == 9
m_map[1][0] == 10
m_map[1][1] == 11
m_map[1][2] == 12
m_map[1][3] == 13
m_map[1][4] == 14
m_map[1][5] == 15
m_map[1][6] == 16
m_map[1][7] == 17
m_map[1][8] == 18
m_map[1][9] == 19
m_map[2][0] == 20
m_map[2][1] == 21
m_map[2][2] == 22
m_map[2][3] == 23
m_map[2][4] == 24
m_map[2][5] == 25
m_map[2][6] == 26
m_map[2][7] == 27
m_map[2][8] == 28
m_map[2][9] == 29
m_map[3][0] == 30
m_map[3][1] == 31
m_map[3][2] == 32
m_map[3][3] == 33
m_map[3][4] == 34
m_map[3][5] == 35
m_map[3][6] == 36
m_map[3][7] == 37
m_map[3][8] == 38
m_map[3][9] == 39
m_map[4][0] == 40
m_map[4][1] == 41
m_map[4][2] == 42
m_map[4][3] == 43
m_map[4][4] == 44
m_map[4][5] == 45
m_map[4][6] == 46
m_map[4][7] == 47
m_map[4][8] == 48
m_map[4][9] == 49
Hope the above helps.
Thanks,
Bio.
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hi...I am new in the field of ATL...Please suggest some books which take the reader from Beginning to programming stage...
thanks...
utkarsh sharma
"Not everything that counts can be counted, and not everything that can be counted counts."
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The best ATL book so far I've read is ATL Internals[^], by Brent Rector and Chris Sells.
That book together with Essential COM[^] by Don Box is a perfect combo for learning COM. If you're new to COM, I'd suggest you start with Essential COM.
--
You're entertaining at least.
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thanks..for the names ATL Internal and Essential COM...
utkarsh sharma
"Not everything that counts can be counted, and not everything that can be counted counts."
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Hi,,
I make an activeX Control using ATL
I added a full control with the font stock property..
now i want to get notified when this property changes..(after the user changes the property i want to perform some action)...
how can i do this ?
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Take a look at the CStockPropImpl source code (atlctl.h). There you will find code like this:
HRESULT STDMETHODCALLTYPE put_Font(IFontDisp* pFont)
{
...
__if_exists(T::OnFontChanged)
{
pT->OnFontChanged();
}
...
}So, for the property Font you add the OnFontChanged function. For the property Picture, you add OnPictureChanged, etc.
--
They say the most horrible things, but I hear violins.
When I close my eyes, I'm at the center of the sun.
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thank you for the reply but i revised put_Font and it does not contain that code ..
Do you use ATL 7.0 ?
I use ATL 3.0 with VC++6 and I need to implement this functionaliy..
Can you help with this ?
maybe by implementing the OnChange(DISPID) function of IPropertyNotifySink..
Can you help me with this ?
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Sorry, I don't have/use ATL3, so I don't have a fast solution for you.
However, you can always override put_Font et al, and chain the call back to CStockPropImpl<...>::put_Font. If the chain call returns S_OK, then you know the font has been set, and you can perform your specific action.
--
They say the most horrible things, but I hear violins.
When I close my eyes, I'm at the center of the sun.
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thanks again
seems this will be the solution till i get the idea .. or till i use ATL 7.0
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I have the code exactly like the sample OnlineAddressBook from the MSDN library yet I get the error whereas that app does not. Such simple things can stop a programmer for hours.
Here is the code I am using. Note that the Web Service this code is in compiles fine, it's when I compile the SRF (ATL Server) project that the error occurs, let me know if you need to see more code.
// DataConsumerWS.h : Defines the ATL Server request handler class
//
#pragma once
namespace DataConsumerWSService
{
const wchar_t MYDATASOURCE[] = L"Provider=SQLOLEDB.1ersist Security Info=False;User ID=me;Initial Catalog=mine;Data Source=SERVER;Use Procedure for Prepare=1;Auto Translate=Trueacket Size=4096;Use Encryption for Data=False;Tag with column collation when possible=False";
// all struct, enum, and typedefs for your webservice should go inside the namespace
// IDataConsumerWSService - web service interface declaration
//
[
uuid("2E179D71-E436-42EE-A1D6-00758BF3D7AA"),
object
]
__interface IDataConsumerWSService
{
// HelloWorld is a sample ATL Server web service method. It shows how to
// declare a web service method and its in-parameters and out-parameters
[id(1)] HRESULT GetStudents([out] int *arrSize,[out,size_is(*arrSize)] BSTR **NameList,[out,size_is(*arrSize)] LONG **IDList);
// TODO: Add additional web service methods here
};
// DataConsumerWSService - web service implementation
//
[
request_handler(name="Default", sdl="GenDataConsumerWSWSDL"),
soap_handler(
name="DataConsumerWSService",
namespace="urn:DataConsumerWSService",
protocol="soap"
)
]
class CDataConsumerWSService :
public IDataConsumerWSService
{
public:
// uncomment the service declaration(s) if you want to use
// a service that was generated with your ISAPI extension
CDataConnection m_dc;
HTTP_CODE InitializeHandler(AtlServerRequest *pRequestInfo, IServiceProvider *pProvider)
{
if (HTTP_SUCCESS != CSoapHandler::InitializeHandler(pRequestInfo, pProvider))
return HTTP_FAIL;
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Never mind. The problem with using MSDN samples is not being clear on Wizard options selected. Anyway, as I was perusing the process of running sproxy.exe for Console App linkage to ATL Web Services, I came across the .wsdl file that needed to be generated. .NET Studio does this under the Add Rerferences utility, however you first have to open the .disco file to get the http path to your web service. Studio then generates the XML document to link your client to the soap handlers ( .wsdl file). Tis done and tis works.
Whew!
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Hello,
I have a appWizard generated ATL project "with MFC support" (VC++ 6.0 SP5). I try to use Project->Add to Project->Files to add a MFC class (.cpp & .h files). The class shows up in the class view but Class Wizard does not recognize the existance of the new class.
Am I doing something wrong? Any suggestions or different ways to do this. Using Add "New" class works, but I need to use an existing class from files, I do not what to have to recreate a bunch of classes from scratch.
Thanks,
Joe Colosi
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