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istream_iterator ... segmentation fault ?

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Join Date: Jan 2008

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kux

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istream_iterator ... segmentation fault ?

Feb 12th, 2008

i have a problem... i wanna make a function that takes a string as input splits it, storing the resulting strings in a vector<string> and then sort it

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
#include <vector>
#include <iterator>
#include <sstream>
 
using namespace std;
 
vector<string> split( const string &sInput  )
{
	istringstream is( sInput );
	vector<string> vect;
	copy( istream_iterator<string>(is) , istream_iterator<string>() , vect.begin() );
	sort( vect.begin() , vect.end() );
	return vect;
 
}
 
int main(int argc, char* argv[])
{
	if(argc != 2) return 1;
	string sForSplit = argv[1];
	vector<string> vect;
	vect = split( sForSplit );
	ostream_iterator<string> os( cout ,"\n");
	copy ( vect.begin(), vect.end() , os );
 
}
#include <iostream>
#include <vector>
#include <iterator>
#include <sstream>

using namespace std;

vector<string> split( const string &sInput  )
{
	istringstream is( sInput );
	vector<string> vect;
	copy( istream_iterator<string>(is) , istream_iterator<string>() , vect.begin() );
	sort( vect.begin() , vect.end() );
	return vect;

}

int main(int argc, char* argv[])
{
	if(argc != 2) return 1;
	string sForSplit = argv[1];
	vector<string> vect;
	vect = split( sForSplit );
	ostream_iterator<string> os( cout ,"\n");
	copy ( vect.begin(), vect.end() , os );

}

it compiles, but when i run it i get Segmentation Fault

can anyone explain me why? i don't want to implement the function without the istream_iterator, done that before, i just want to know where does the runtime error occur and why.
thx

Last edited by Narue; Feb 12th, 2008 at 5:26 pm. Reason: Fixed code tags

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Narue

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Re: istream_iterator ... segmentation fault ?

Feb 12th, 2008

>vector<string> vect;
>copy( istream_iterator<string>(is) , istream_iterator<string>() , vect.begin() );
The vector is empty, and copy won't call push_back for you. You need to add a back_inserter to the destination or copy will write to memory that you don't own:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
copy( istream_iterator<string>(is) ,
  istream_iterator<string>() , back_inserter( vect ) );
copy( istream_iterator<string>(is) ,
  istream_iterator<string>() , back_inserter( vect ) );

You also need to include <algorithm> if you plan to use the sort function.

I'm here to prove you wrong.

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Join Date: Jan 2008

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kux

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Re: istream_iterator ... segmentation fault ?

Feb 12th, 2008

•

Originally Posted by Narue

>vector<string> vect;
>copy( istream_iterator<string>(is) , istream_iterator<string>() , vect.begin() );
The vector is empty, and copy won't call push_back for you. You need to add a back_inserter to the destination or copy will write to memory that you don't own:
Help with Code Tags

C++ Syntax (Toggle Plain Text)
copy( istream_iterator<string>(is) ,
  istream_iterator<string>() , back_inserter( vect ) );
copy( istream_iterator<string>(is) , istream_iterator<string>() , back_inserter( vect ) );
You also need to include <algorithm> if you plan to use the sort function.