Re: [Boost-users] [ptr_container][ptr_map]

On 13-09-2014 22:52, Aaron Levy wrote:

Consider the following code:

I can create a ptr_set of Base like this:

boost::ptr_set<Base> set;

But I can't create a ptr_map with Base as key, like this:

boost::ptr_map map;

The problem is that Base is abstract and so the key cannot be instantiated by ptr_map. What is the cause for this distinction between ptr_set and ptr_map.

I guess it might be possible, but the work involved was probably large. The workaround is boost::ptr_map although it's probably not a great workaround, depending on what semantics you are looking for. IIRC, the map interface was not really easy to adopt for a key that is polymorphic. regards -Thorsten