Some sort of append algorithm...

[deancoo]

I'm looking for an STL algorithm similar to 'copy', but not needing the
target container to have elements available to copy into (a 'valid range').
What I need to do is something simple like, take all the elements in
container A and append them to the end of container B (sorting is not
necessary). I've looked at set_union and merge, but they don't seem to do
the trick.

d

 

[Jonathan Turkanis]

I'm looking for an STL algorithm similar to 'copy', but not needing
the target container to have elements available to copy into (a
'valid range'). What I need to do is something simple like, take all
the elements in container A and append them to the end of container B

If B is a sequence supporting push_back, you can write:

std::copy(A.begin(), A.end(), std::back_inserter(B));

(sorting is not necessary). I've looked at set_union and merge, but
they don't seem to do the trick.

d

Jonathan

 

[deancoo]

If B is a sequence supporting push_back, you can write:

std::copy(A.begin(), A.end(), std::back_inserter(B));

Jonathan

Why yes you can. Thanks Jonathan. That's going to save me allot of time
and complication. Is "back_inserter" is a member function of the sequence?
An algorithm of its own? I can't seem to find any reference to it.

d

 

[Jonathan Turkanis]

Why yes you can. Thanks Jonathan. That's going to save me allot of
time and complication. Is "back_inserter" is a member function of
the sequence? An algorithm of its own? I can't seem to find any
reference to it.

I guess I should have been more explicit. Include the standard header
<iterator>. This contains the definition of the clas template
back_insert_iterator, whose instances insert elements at the end of a container,
and the helper function back_inserter, which takes a reference to a container
and returns an instance of an appropriate specialization of
back_insert_iterator.

There's also an insert_iterator and front_insert_iterator.

d

Jonathan

 

[davidrubin]

It's in the 'iterator' header file. It's a function template in the
'std' namespace. /david