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Hi all,
I need a help relatd to removing the part of string
std::string bDesc ="hi how(Temp) are(Temp) you.i am(Temp) Great"
int p=bDesc.find("(",0);
int j=bDesc.find(")",0);
if(p>0 && j>0)
{
bDesc.erase(p,j);
}
from above string i want to remove (Temp) but i am able to remove only once .. do i need to loop through each character.....
can some body help me...
vikas da
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You missed loop.
Regards,
Paresh.
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I know what i want here ...do i need to loops through each character....
or any other efficient and faster way exists...
vikas da
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Is it possible to use MFC? In that case, you can use CString::Replace()[^] and get them replaced in one function call.
Regards,
Jijo.
_____________________________________________________
http://weseetips.com[ ^] Visual C++ tips and tricks. Updated daily.
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Jijo raj wrote: Is it possible to use MFC?
Possible but not advisable (MFC is deprecated  ).
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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std::string bDesc ="hi how(Temp) are(Temp) you.i am(Temp) Great";
std::string bToken = "(Temp)";
size_t len = bToken.length();
size_t pos = 0;
while (( pos = bDesc.find(bToken,pos)) != std::string::npos)
{
bDesc.erase(pos,len);
}
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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Thanks everybody ...
i have Implimented ..Pallini code... its working good for me..
earlier i looped through each character of the string thats was tough
Token concept is good..
Thank Pallini
vikas da
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when you have a method prototype as such:
<code>
void setCacheBlocks(vector<cacheblock> const &value);
</cacheblock></code>
and an implementation as such:
<code>
void Simulator::setCacheBlocks(vector<cacheblock> const & value)
{
m_CacheBlock = value;
}
</cacheblock></code>
And when you run the code, the size of items in the vector is correct, but the actual contents of each object contained by the vector magically disappears?
here's what's actually happening (keep in mind this is a mutation of several generations)
<code>
void Simulator::Simulate()
{
Splash();
getUserSettings();
cout.clear();
cout << "Reading trace file..." << endl;
GetData();
sleep(2);
cout << "\nData read.\nStarting Simulation..." << endl;
sleep(1);
// simulation start
//create the data blocks and the cache sets
//create the Cache Blocks
CreateCacheBlocks();
//create the Cache Sets
CreateCacheSets();
}
void Simulator::CreateCacheBlocks()
{
uint numBlocks = getSettings().getCacheSize()/getSettings().getBlocksSize();
uint maxOffset = getSettings().getOffsetParity();
uint bTag = getSettings().getTagParity();
uint bIndex = getSettings().getIndexParity();
bool isValid = false;
char* bData = new char[maxOffset - 1]; //just to make it 0 based
for(int i = 0; i < maxOffset; i++)
{
bData[i] = NULL;
}
vector<cacheblock> v;
CacheBlock cb;
cb.Initialize(maxOffset,bTag,bIndex,isValid,bData);
cb.setSettings(m_Settings);
//initialize each cache block to an initial state
for(uint i = 0; i < numBlocks; i++)
{
cb.setBlockNumber(i);
cb.setBlockAddress(cb.CalculateBlockAddress(i));
v.push_back(cb);
}
//TODO: fix this ASAP
//setCacheBlocks(v);
m_CacheBlock = v;
}
void Simulator::CreateCacheSets()
{
uint numBlocks = getSettings().getCacheSize()/getSettings().getBlocksSize();
uint numSets = numBlocks/getSettings().getCacheAssociativity();
uint numBlocksPerSet = numBlocks / numSets;
CacheSet cs;
cs.setSettings(getSettings());
vector<cacheset> v;
//create the correct number of sets and assign their set indexes
for(uint i = 0; i < numSets; i++)
{
cs.setSetIndex(i);
v.push_back(cs);
}
int k = v.size();
CacheBlock cb;
//assign each cache block to its set
uint setIx = 0;
for(uint i = 0; i < numBlocks; i++)
{
setIx = getCacheBlocks()[i].getBlockAddress() << getSettings().getTagParity();
setIx >>= getSettings().getTagParity();
//cb = getCacheBlocks()[i];
cb = m_CacheBlock[i]; //this statement should be exactly like the preceding one in worth
v[setIx].getCacheBlocks().push_back(cb);
}
setCacheSet(v);
}
</cacheset></cacheblock></code>
If you look to the method Simulate, everything works fine, including CreateCacheBlocks(), but things go belly up in CreateCacheSets().
Yes, I know I shouldn't be using getXX()/setXX() but this is the second time I've had to deal with this Prof and he's old and really old school and doesn't want to get with the times of using overloaded methods.
Don't forget to vote if the response was helpful
Sig history
"dad" Ishmail-Samuel Mustafa
Unix is a Four Letter Word, and Vi is a Two Letter Abbreviation
"There is no wealth like knowledge, no poverty like ignorance" Ali Ibn Abi Talib
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Your post is very difficult to read (don't check the "ignore html tags" otherwise the code tags won't work).
You are talking about danling pointers. Where are those pointers because I don't see any pointers in your code...
Mustafa Ismail Mustafa wrote: And when you run the code, the size of items in the vector is correct, but the actual contents of each object contained by the vector magically disappears?
Could you explain that with a bit more details ? You mean that the contents of all the cacheblock objects stored in your vector are destroyed ? Can you show the details of the cacheblock class ?
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Cedric Moonen wrote: Your post is very difficult to read (don't check the "ignore html tags" otherwise the code tags won't work).
Stuff like vector<xyz> v aren't obvious then.
I assumed there are dangling pointers because the objects have values that are not what they were so its like a temporary value that has disappeared.
Cedric Moonen wrote: Could you explain that with a bit more details ? You mean that the contents of all the cacheblock objects stored in your vector are destroyed ? Can you show the details of the cacheblock class ?
Precisely.
I'll email them since they're on my Linux VM and for some reason, the bidirectional clipboard just stopped working.
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Mustafa Ismail Mustafa wrote: Stuff like vector<xyz> v aren't obvious then
It's not too difficult to use < and > instead - you're more likely to get an answer if your question's nicely formatted, if only because then people can read it
Mustafa Ismail Mustafa wrote: I assumed there are dangling pointers because the objects have values that are not what they were so its like a temporary value that has disappeared.
You have no explicit pointers in your code. It's more likely that you have a dangling reference - possibly a reference to a local that disappeared when a function completed?
I presume you've stepped through with the debugger, seeing when the values of the objects change? Setting a data breakpoint can help.
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Stuart Dootson wrote: It's not too difficult to use < and > instead - you're more likely to get an answer if your question's nicely formatted, if only because then people can read it
I did that in the following two postings back to Cedric. I was being lazy I suppose.
Stuart Dootson wrote: You have no explicit pointers in your code. It's more likely that you have a dangling reference - possibly a reference to a local that disappeared when a function completed?
Aha! Live and re-learn.
Stuart Dootson wrote: I presume you've stepped through with the debugger, seeing when the values of the objects change? Setting a data breakpoint can help.
Certainly. I program in C# and previously Java. The last time I touched C++ was almost 8 years ago, coupled with what I believe is an extremely lacking IDE (netbeans 6.5) on Linux is proving a pain. Gimme Eclipse or VS any day. This is why I seem to be asking really pathetically sounding questions
I come and post after I've given up and then its a matter of re-learning.
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Looking at your code, m_Settings and m_BlockData in CacheBlock are certainly iffy. You copy pointers to these items, but I suspect you should really copy the contents. Especially when (from the Simulator::CreateCacheBlocks code) it looks like all your cache-blocks will be sharing the same block data with your current implementation.
Memory management in C++ certainly can be a pain - that's why I try to always use objects that manage it for you, such as std::vectors or Boost shared pointers/shared arrays[^].
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Sadly Stuart, those are the two I'm not having problems with. Its the rest of the class.
If you'll look below, that's where all the fuss is happening.
I'd like to direct your kind attention to the methods CreateCacheBlocks() and CreateCacheSets() in particular the latter. It is then that the contents of the CacheBlock object retrieved by getCacheBlocks()[i] is incorrect and that is where I'm losing my mind because it was in the preceding function CreateCacheBlocks() that I set the values (correctly I might add).
If you're wondering what this is, its the framework for a cache simulator for my Computer Arch II class at university where after I'm supposed to be simulating different algorithms and trying to make them better through changing one thing or another.
<br />
#ifndef _SIMULATOR_H<br />
#define _SIMULATOR_H<br />
<br />
<br />
#define DEBUG<br />
<br />
#include <iostream><br />
#include <vector><br />
#include "definitions.h"<br />
#include "settings.h"<br />
#include "filereader.h"<br />
#include "cacheset.h"<br />
#include "cacheblock.h"<br />
<br />
<br />
using namespace std;<br />
<br />
class Simulator<br />
{<br />
<br />
public:<br />
Simulator();<br />
Simulator(const Simulator& orig);<br />
virtual ~Simulator();<br />
<br />
void getUserSettings();<br />
void GetData();<br />
void Simulate();<br />
void Splash();<br />
<br />
void CreateCacheBlocks();<br />
void CreateCacheSets();<br />
<br />
<br />
Settings getSettings() const;<br />
void setSettings(Settings const &value);<br />
<br />
<br />
<br />
vector<CacheSet> getCacheSet() const;<br />
void setCacheSet(vector<CacheSet> const &value);<br />
<br />
<br />
vector<CacheBlock> getCacheBlocks() const;<br />
void setCacheBlocks(vector<CacheBlock> const &value);<br />
<br />
<br />
vector<uint> getDataBuffer() const;<br />
void setDataBuffer(vector<uint> const &value);<br />
<br />
private:<br />
Settings m_Settings;;<br />
vector<CacheBlock> m_CacheBlock;<br />
vector<CacheSet> m_CacheSet;<br />
vector<uint> m_DataBuffer;<br />
<br />
};<br />
<br />
#endif /* _SIMULATOR_H */<br />
</vector></iostream>
***********************************************
<br />
#include "simulator.h"<br />
#include <vector><br />
#include "cacheset.h"<br />
<br />
<br />
Simulator::Simulator()<br />
{<br />
m_Settings.setAccessesToSimulate(0);<br />
m_Settings.setBlockSize(0);<br />
m_Settings.setCacheAssociativity(0);<br />
m_Settings.setCachePolicy(Settings::LRU);<br />
m_Settings.setCacheSize(0);<br />
}<br />
<br />
Simulator::Simulator(const Simulator& orig)<br />
{<br />
}<br />
<br />
Simulator::~Simulator()<br />
{<br />
}<br />
<br />
<br />
<br />
void Simulator::getUserSettings()<br />
{<br />
#ifdef DEBUG<br />
Settings s;<br />
s.setDefault();<br />
setSettings(s);<br />
<br />
return;<br />
#endif<br />
<br />
<br />
}<br />
<br />
void Simulator::GetData()<br />
{<br />
FileReader fr;<br />
Settings s;<br />
s = getSettings();<br />
setDataBuffer(fr.ReadFile(s));<br />
<br />
}<br />
<br />
<br />
void Simulator::Simulate()<br />
{<br />
Splash();<br />
<br />
getUserSettings();<br />
<br />
cout.clear();<br />
cout << "Reading trace file..." << endl;<br />
<br />
GetData();<br />
sleep(2);<br />
<br />
cout << "\nData read.\nStarting Simulation..." << endl;<br />
sleep(1);<br />
<br />
<br />
<br />
CreateCacheBlocks();<br />
<br />
CreateCacheSets();<br />
<br />
}<br />
<br />
void Simulator::CreateCacheBlocks()<br />
{<br />
<br />
uint numBlocks = getSettings().getCacheSize()/getSettings().getBlocksSize();<br />
<br />
<br />
<br />
uint maxOffset = getSettings().getOffsetParity();<br />
uint bTag = getSettings().getTagParity();<br />
uint bIndex = getSettings().getIndexParity();<br />
bool isValid = false;<br />
char* bData = new char[maxOffset - 1];
for(int i = 0; i < maxOffset; i++)<br />
{<br />
bData[i] = NULL;<br />
}<br />
<br />
<br />
vector<CacheBlock> v;<br />
<br />
CacheBlock cb;<br />
cb.Initialize(maxOffset,bTag,bIndex,isValid,bData);<br />
<br />
cb.setSettings(m_Settings);<br />
for(uint i = 0; i < numBlocks; i++)<br />
{<br />
cb.setBlockNumber(i);<br />
cb.setBlockAddress(cb.CalculateBlockAddress(i));<br />
v.push_back(cb);<br />
}<br />
setCacheBlocks(v);<br />
<br />
#ifdef DEBUG<br />
cout << "\n\n" << endl;<br />
cout << "Vector Length: \t" << getCacheBlocks().size() << endl;<br />
<br />
cout << "\n\n" << endl;<br />
<br />
for(int i = 0; i < getCacheBlocks().size(); i++)<br />
{<br />
cout << "v[" << i << "].BlockAddress = \t" << v[i].getBlockAddress() << endl;<br />
}<br />
#endif<br />
}<br />
<br />
void Simulator::CreateCacheSets()<br />
{<br />
<br />
<br />
uint numBlocks = getSettings().getCacheSize()/getSettings().getBlocksSize();<br />
uint numSets = numBlocks/getSettings().getCacheAssociativity();<br />
<br />
uint numBlocksPerSet = numBlocks / numSets;<br />
<br />
<br />
CacheSet cs;<br />
cs.setSettings(getSettings());<br />
vector<CacheSet> v;<br />
<br />
for(uint i = 0; i < numSets; i++)<br />
{<br />
cs.setSetIndex(i);<br />
v.push_back(cs);<br />
}<br />
<br />
int k = v.size();<br />
CacheBlock cb;<br />
<br />
uint setIx = 0;<br />
for(uint i = 0; i < numBlocks; i++)<br />
{<br />
<br />
setIx = getCacheBlocks()[i].getBlockAddress() << getSettings().getTagParity();<br />
setIx >>= getSettings().getTagParity();<br />
cb = m_CacheBlock[i];<br />
v[setIx].getCacheBlocks().push_back(cb);<br />
}<br />
<br />
#ifdef DEBUG<br />
int j = v.size();<br />
<br />
for(int i = 0; i < v.size(); i++)<br />
{<br />
j = v[i].getCacheBlocks().size();<br />
cout << "V[i][j].size() =" << j << endl;<br />
}<br />
#endif<br />
<br />
setCacheSet(v);<br />
<br />
#ifdef DEBUG<br />
<br />
cout << "\n" << endl;<br />
cout << "Number of Sets:\t\t" << v.size() << endl;<br />
cout << "Number of blocks in each set:\t" <<<br />
v[0].getCacheBlocks().size() << endl;<br />
cout << "\n" << endl;<br />
for(int i = 0; i < v.size(); i++)<br />
{<br />
cout << "Cache set:\t" << i << endl;<br />
cout << "\n" << endl;<br />
for(int j = 0; j < v[i].getCacheBlocks().size(); j++)<br />
{<br />
cout << "Block number " << j << "\tBlock Address: " << v[i].getCacheBlocks()[i].getBlockAddress();<br />
}<br />
cout << "\n" << endl;<br />
}<br />
#endif<br />
<br />
}<br />
<br />
<br />
<br />
void Simulator::Splash()<br />
{<br />
cout.clear();<br />
<br />
cout << "Starting Cache Simulation by Steve Mustafa\n\n" << endl;<br />
cout << "Supervisor: Dr. Mazen Kharbutli\nComputer Architecture II\n" << endl;<br />
<br />
sleep(5);<br />
}<br />
<br />
<br />
<br />
<br />
Settings Simulator::getSettings() const<br />
{<br />
return m_Settings;<br />
}<br />
<br />
<br />
void Simulator::setSettings(Settings const &value)<br />
{<br />
m_Settings = value;<br />
}<br />
<br />
<br />
vector<CacheSet> Simulator::getCacheSet() const<br />
{<br />
return m_CacheSet;<br />
}<br />
<br />
void Simulator::setCacheSet(vector<CacheSet>const &value)<br />
{<br />
<br />
int j = m_CacheSet.size();<br />
m_CacheSet = value;<br />
j = m_CacheSet.size();<br />
j = getCacheSet().size();<br />
}<br />
<br />
<br />
vector<CacheBlock> Simulator::getCacheBlocks() const<br />
{<br />
return m_CacheBlock;<br />
}<br />
<br />
void Simulator::setCacheBlocks(vector<CacheBlock> const & value)<br />
{<br />
m_CacheBlock = value;<br />
int j = m_CacheBlock.size();<br />
j = getCacheBlocks().size();<br />
}<br />
<br />
<br />
vector<uint> Simulator::getDataBuffer() const<br />
{<br />
return m_DataBuffer;<br />
}<br />
<br />
void Simulator::setDataBuffer(vector<uint> const &value)<br />
{<br />
m_DataBuffer = value;<br />
}<br />
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I'm a f**king idiot. I've built your code and stepped through it with GDB (well, Xcode on my Mac) and just realised what the problem is, when it should have been immediately obvious.
The trouble is your copy constructors - they're not doing anything! Which means that as they're used when copying items into a vector using push_back, the vector gets set with empty items.
Anyway - you can rely on the default copy constructor and assignment operator if member-wise copy is adequate for your structure. Member-wise is fine unless you need to do some sort of resource management (e.g. memory allocation/deallocation).
Hope that sorts you out!
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OK, firstly, Stu, let me just say thank you for being so patient in helping me solve this continuing issue. Your patience is model.
Secondly, I have discovered another problem and I've easily spent 4 hours on it trying to figure out how the hell its happening. Really, in the class "Simulator" even though we have
<br />
vector<cacheset> getCacheSet() const;<br />
void setCacheSet(vector<cacheset> const & value);<br />
<br />
vector<cacheblock> getCacheBlock() const;<br />
void setCacheBlock(vector<cacheblock> const & value);<br />
</cacheblock></cacheblock></cacheset></cacheset>
the actions are local to that subroutine (I'm looking at CreateCacheBlocks() and CreateCacheSets()) and are not acting on the class instance. Ultimately, the question is why? How can I be moving in a proper functional sequence in 2 different instances? What the hell am I forgetting?
I've implemented the copy constructors for the CacheSet and CacheBlock classes as you've suggested and they've alleviated the previous problems, but somehow, I get the feeling that the current issue I'm facing is a continuation of the previous one.
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Mustafa Ismail Mustafa wrote: the actions are local to that subroutine (I'm looking at CreateCacheBlocks() and CreateCacheSets()) and are not acting on the class instance. Ultimately, the question is why? How can I be moving in a proper functional sequence in 2 different instances? What the hell am I forgetting?
Not really sure what you mean - what are you seeing vs what would you expect to see?
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Basically, when I'm calling CreateCacheBlocks() I'm creating a vector of CacheBlock objects, initialized to whatever initial values it should have determined by user input previously acquired in the application (currently simply defaulting it). CreateCacheSets() is supposed to create a number of sets (dependent on the associativity selected) after which, it assigns specific CacheBlocks to each set (basic Cache and Cache Associativity).
What I've noticed is that CreateCacheBlocks() creates the vector and its contents correctly and I've checked this at the end of the method and as soon as I exit the method back to the method Simulate, however, when the call to CreateCacheSets is made, the vector CacheBlocks is empty. How the hell did that happen?
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That still sounds like copy constructor or assignment operator issues - could you post the code for those that you've now implemented?
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Sorry this took some time, my system just crashed and I spent the last hour just restoring order.
Here's the Copy Constructors:
<br />
CacheSet(const CacheSet& orig);
<br />
CacheSet::CacheSet(const CacheSet& orig)
{<br />
setSettings(orig.getSettings());<br />
setBlockCount(orig.getBlockCount());<br />
setBlockSize(orig.getBlockSize());<br />
setSetIndex(orig.getSetIndex());<br />
setCacheBlocks(orig.getCacheBlocks());<br />
}<br />
<br />
CacheBlock(const CacheBlock& orig);
<br />
CacheBlock::CacheBlock(const CacheBlock& orig)
{<br />
setSettings(orig.getSettings());<br />
setBlockAddress(orig.getBlockAddress());<br />
setBlockData(orig.getBlockData());<br />
setBlockIndex(orig.getBlockIndex());<br />
setBlockTag(orig.getBlockTag());<br />
setBlockNumber(orig.getBlockNumber());<br />
setIsValid(orig.getIsValid());<br />
setMaxBlockOffset(orig.getMaxBlockOffset());<br />
setTimeStamp(orig.getTimeStamp());<br />
}<br />
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Mmmm - I'm not seeing what you're seeing - m_CacheBlocks retains its value. However, I've found some more issues in your code:
getCacheBlocks returns the cache-block vector by value - try returning by const reference instead:
vector<CacheBlock> const & getCacheBlocks() const; - Some of your setter functions take a
uint by non-const reference - they should probably be by value (that's fine with plain old data like integers) or const reference. VC++ complained about it, anyway.
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I have taken your advice and currently have given up developing on Linux, I can't make good use of my time using IDEs that I don't have much experience in and on top of that using a language that I obviously am completely out of practice with (MUCH more so than I thought  )
I've moved back to Windows (VS2008) at least the debugger is something of an old friend. I'll keep you posted mate.
Thanks a zillion.
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Mustafa Ismail Mustafa wrote: I've moved back to Windows (VS2008) at least the debugger is something of an old friend
Can't say I blame you - even using GDB through Xcode felt...strange, given how used to Visual Studio I am!
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I've pinpointed the exact location where the error takes place.
Guess what? Its a const correctness issue.
Simulator::CreateCacheSets()
{
...
getCacheSets[setIx].getCacheBlocks().push_back(getCacheBlocks()[i]);
...
}
getCacheBlocks() returns a const object. I'm surprised a compile time error was not thrown. Do I overload the method?
[update]
I've fixed it, but its the ugliest hack I've ever done.
<br />
<br />
vector<cacheblock> cbs;<br />
for(uint i = 0; i < numBlocks; i++)<br />
{<br />
ba = getCacheBlocks()[i].getBlockAddress();<br />
setIx = ba % numSets;<br />
cbs = v[setIx].getCacheBlocks();<br />
cbs.push_back(this->getCacheBlocks()[i]);<br />
v[setIx].setCacheBlocks(cbs);<br />
}<br />
</cacheblock>
Just sick and as ugly as sin.
Stuart, thanks a million mate for all your patience. When I do pass by Brittania, an hour's worth of pints is on me 
modified on Wednesday, December 17, 2008 12:14 PM
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Mustafa Ismail Mustafa wrote: Do I overload the method
You can't overload purely on return type - in C++ (unlike Ada), function signatures don't include return types.
I may have given you some bad advice suggesting you return by const reference - a non-const reference would be better in this case.
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