Swapping a single pointer item in vector?

[Howard]

Hi all,
is there an easy way to swap one pointer item in a vector with a pointer
that's not yet in the vector?

Currently, I'm using begin()+index to get an iterator to the item I want
to swap out, then deleting the pointer there, then using erase to get rid of
the vector item itself and get an iterator to the next item, and finally
using insert to put my new pointer in the correct place. Is there an easier
way?

Thanks,
-Howard

 

[Alf P. Steinbach]

* Howard:

is there an easy way to swap one pointer item in a vector with a
pointer that's not yet in the vector?

std::swap comes to mind.

Cheers, & hth.,

- Alf

 

[Jim Langston]

Hi all,
is there an easy way to swap one pointer item in a vector with a
pointer that's not yet in the vector?

Currently, I'm using begin()+index to get an iterator to the item I
want to swap out, then deleting the pointer there, then using erase to get
rid of the vector item itself and get an iterator to the next item, and
finally using insert to put my new pointer in the correct place. Is there
an easier way?

Just change it. The output of the following program is
10 20
10 10

#include <iostream>
#include <vector>

int main()
{
std::vector<int*> MyVect;
int a = 10;
int b = 20;

MyVect.push_back( &a );
MyVect.push_back( &b );

for ( std::vector<int*>::iterator it = MyVect.begin(); it !=
MyVect.end(); ++it )
std::cout << *(*it) << " ";
std::cout << "\n";

std::vector<int*>::iterator it = MyVect.begin() + 1;
*it = &a;

for ( std::vector<int*>::iterator it = MyVect.begin(); it !=
MyVect.end(); ++it )
std::cout << *(*it) << " ";
std::cout << "\n";
}

 

[Howard]

----- Original Message -----
From: "Jim Langston" <[email protected]>
Newsgroups: comp.lang.c++
Sent: Tuesday, December 04, 2007 7:01 PM
Subject: Re: Swapping a single pointer item in vector?

Just change it. std::vector<int*>::iterator it = MyVect.begin() + 1;
*it = &a;

D'oh! Of course! Thanks, Jim
-Howard