copy algorithm:segmentation fault error appears

[utab]

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <iterator>

using std::cout;
using std::vector;
using std::string;
using std::endl;
using std::copy;
using std::back_inserter;

int main(){

vector<string> str;
vector<string>::iterator iterb = str.begin(),iter=str.begin();
vector<string>::iterator itere = iterb+11;
vector<string>::size_type i = 0;
vector<string> dest;

while(iter!=itere){

*(iter)="string";

iter++;
}

copy(iterb,itere,back_inserter(dest));

while(i!=dest.size()){

cout << dest[i];
i++;
}

return 0;

}

Why?

[Ben Pope]

utab wrote:

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <iterator>

using std::cout;
using std::vector;
using std::string;
using std::endl;
using std::copy;
using std::back_inserter;

int main(){

vector<string> str;
vector<string>::iterator iterb = str.begin(),iter=str.begin();
vector<string>::iterator itere = iterb+11;
vector<string>::size_type i = 0;
vector<string> dest;

while(iter!=itere){

*(iter)="string";

iter++;
}
OK, itere points to the 11th element of str, which is an empty vector.
It has no 11th element, nor a first.

Use a for loop counting between 0 and 11, and use use push_back within it.

After that, initialise itere with str.end().
copy(iterb,itere,back_inserter(dest));

while(i!=dest.size()){

cout << dest[i];
i++;
}
Instead you can use copy (as above), and an ostream_iterator.
return 0;

}

Why?

Assigning to elements in the vector that have not been allocated.

Techniques to fix that:
1) Don't declare variables until you can properly initialise them (see
itere, which should be initialised as str.end())
2) Don't create random offsets of iterators if you don't need to. (the 11)

Read up on push_back and ostream_iterator.

Post the code you end up with here again, and we'll have another look.

Ben Pope
--
I'm not just a number. To many, I'm known as a string...