Re: [Boost-users] [boost-users] [assign] std::vector initialisation by boost::assign::list_of

17 Mar 2010

      mmmm...

Actually, I would probably create an empty vector and use the list_of in the
constructor's body.

Another idea I just came up with, is to use an transforming iterator, which
iterates over the list_of instance and additionally can be compared with a
default constructed iterator instance. Smth like:

vector<int> v(my_iterator(list_of(1)(2)), my_iterator());

Regards,
Ovanes

On Wed, Mar 17, 2010 at 4:16 PM, Ovanes Markarian wrote:
...
Actually I tested some of them with gcc and the only solution I came up to
resolve ambiguity is:
#include 
#include <vector>
#include <iterator>
#include <algorithm>
#include <iostream>
using namespace std;
using namespace boost;
using namespace boost::assign;
int main(int argc, char* argv[])
{
  typedef vector<int> int_vec;
  int_vec v = list_of(1)(2);
  int_vec v2(2);
  v2=list_of(1)(2).to_container(v2);
ostream_iterator<int> oiter(cout, ",");
  copy(v2.begin(), v2.end(), oiter);
}
Hope that helps,
Ovanes
On Wed, Mar 17, 2010 at 1:52 PM, Ovanes Markarian wrote:
...
Sorry, it must be to_container() and not to_adapter().
On Wed, Mar 17, 2010 at 1:51 PM, Ovanes Markarian 
...
wrote:
...
On Wed, Mar 17, 2010 at 1:32 PM, Andrey Torba wrote:
...
The code is compilable on msvc but is not on gcc-4.3:
But the problem occurs when i try to initialise std::vector in a class
initialization list:
class sss
{
  std::vector<int> v;
   sss()
    : v(boost::assign::list_of(1)(2))
  {}
};
What happens if you call:
sss()
    : v(boost::assign::list_of(1)(2).to_adapter())
  {}
list_of implements 2 members:
implicit conversion opertor to the container type and the to_adapter
member. You can cast list_of instance to your vector<int> if that with
adapter does not work. Other solution can be:
If you need efficiency, you still can use the vector ctor which reserves
the number of items in a vector and than copies
the elements from the list.
sss() : v(2)
{
  v = list_of...;
}
Regards,
Ovanes