q: STL vector manipulation

[laniik]

Hi. I have a STL vector of some relativly complicated objects

I was wondering if there was a good way to remove objects from the
middle of the vector.

Currently the only way I know how to remove element i is:

1. set the contents of the object at index i to the contents of the
last object
2. vector.pop_back();

but this is obviously annoying if my objects are not just simple
structs.

Thanks!

Oliver

[Ben]

On 2005-05-26 17:31:10 -0400, "laniik" <[e-mail]> said:

Hi. I have a STL vector of some relativly complicated objects I was wondering if there was a good way to remove objects from the
middle of the vector.

vec.erase(iter);

where vec is your vector, and iter is an iterator to the object you
wish to remove.
--
Clark S. Cox, III
[e-mail]
Or you can do vec.erase(vec.begin() + i) // where i is an integer
for the element #

If you are doing a lot of deleting from the middle then you may not
want to use vectors. A list might be better for you, in which case,
you must use the erase that Clark suggested.

-Benjamin Dacko

[Ioannis Vranos]

Ben wrote:

vec.erase(iter);

where vec is your vector, and iter is an iterator to the object you
wish to remove.
--
Clark S. Cox, III
[e-mail]
Or you can do vec.erase(vec.begin() + i) // where i is an integer
for the element #

Which is the same, an iterator to the object.
--
Ioannis Vranos

http://www23.brinkster.com/noicys

[laniik]

great thanks a lot

oliver

[Stephen Howe]

"laniik" <la****@yahoo.com> wrote in message
news:11*********************@g49g2000cwa.googlegro ups.com...

Hi. I have a STL vector of some relativly complicated objects

I was wondering if there was a good way to remove objects from the
middle of the vector.

You can do

v.erase(remove(v.begin(), v.end(), value), v.end());

which basically translates to "copy all the non-values towards the beginning
of the vector and erase the crud at the end".

So if you had a vector of int's, and there were 16 5's scattered over the
vector, then

v.erase(remove(v.begin(), v.end(), 5), v.end());

would make 1 pass over the vector, compacting all the non-5's and erasing 16
elements at the end.

Stephen Howe

[Ben]

Ben wrote:

vec.erase(iter); where vec is your vector, and iter is an iterator to the object you
wish to remove.
--
Clark S. Cox, III
[e-mail]
Or you can do vec.erase(vec.begin() + i) // where i is an integer
for the element #

Which is the same, an iterator to the object.

--
Ioannis Vranos
http://www23.brinkster.com/noi*cys

Yes, it is an iterator.
I just wanted to show laniik how to do an erase using the same index
that he was using in his step 1.

-Benjamin Dacko