Re: vector.erase(iterator iter) will change "iter" or not?

From:

Richard Herring <junk@[127.0.0.1]>

Newsgroups:

comp.lang.c++

Date:

Thu, 21 Feb 2008 15:31:44 +0000

Message-ID:

<RJCQX4cglZvHFwsR@baesystems.com>

In message <fpk2sg$5du$1@news.datemas.de>, Victor Bazarov
<v.Abazarov@comAcast.net> writes

thomas wrote:

suppose I will delete an element pointed to by "iter".
like this:

vector<int> s;
for(vector<int>::iterator iter=s.begin(); iter!=s.end(); iter++){
if(*iter==3)
s.erase(iter); //A
}

in line A, if element by "iter" is erased, will "iter" point to the
next element(now should be the current element) automatically?

The iterator that refers to the removed element and all elements
after the removed one are invalidated by that operation. IOW, the
Standard makes no attempt to define what the 'iter' would point to
after being erased.

I wonder if the OP is confused because the iterator is passed by value
and therefore not modified? Obviously erase(iter) can't change its
_value_, but it certainly changes its _meaning_ - what it points to is
no longer valid.

(And the higher-level answer to his question is that he should probably
be using std::remove anyway:

s.erase(remove(s.begin(), s.end(), 3), s.end());

)
--
Richard Herring