Re: [boost] [cpo-proposal] presentation of the idea

On 08/20/13 06:55, Larry Evans wrote:

On 08/20/13 04:23, Thorsten Ottosen wrote:

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On 20-08-2013 11:04, Rob Stewart wrote:

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On Aug 19, 2013, at 9:44 AM, Thorsten Ottosen wrote:

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Yes, at this level it is nice to take advantage of the memcopying built into vector<char>.

Here's the problem. Replicating the bits of and object isn't the same as copying it. Many classes store a this pointer or rely on a data member address as a unique key, etc. Copy constructors must run.

Good catch. Thanks Rob.

However, this is a specific case of a more general problem. Suppose the polymorphic_object at container[i+j] contains a pointer of the polymorphic_obect at container[i]. Then after resizing, the pointer will become invalid. The specific case Rob mentions is when j=0. Maybe the class should just warn the user not to do this or suggest a workaround, maybe instead of storing a pointer, just store the index into the container? [snip] -Larry