insert question..

[Mattias B]

Hello!

I have a question about how stl's insert works on containers and on
vector in particular.

The question is: is it OK to insert a value before end() with something
like:

vector<int> v;
v.insert(v.end(), 1);

In SGI's stl documentation it says that the iterator passed to insert
must be a valid iterator in v. Is end() a valid operator or must an
iterator be derefernceable in order to be valid?

Regards,
Mattias

 

[Victor Bazarov]

I have a question about how stl's insert works on containers and on
vector in particular.

The question is: is it OK to insert a value before end() with something
like:

vector<int> v;
v.insert(v.end(), 1);

Yes, it is OK. BTW, that's "push_back"s operational semantics
for 'vector', 'list', and 'deque'.

In SGI's stl documentation it says that the iterator passed to insert
must be a valid iterator in v. Is end() a valid operator or must an
iterator be derefernceable in order to be valid?

No, to be valid an iterator has to be either _to_ an element or
"one past the end". That makes 'end()' a valid iterator, AFAIK.

Victor