Re: [boost] [Boost-users] [BGL] Stoer–Wagner min-cut algorithm

Subject: Re: [boost] [Boost-users] [BGL] Stoer–Wagner min-cut algorithm
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2010-06-24 09:56:50

On Thu, 24 Jun 2010, Barend Gehrels wrote:

> Hi Jeremiah,
>
> I react on this point only:
>
>> 
>> - Property maps are passed by copy; they are intended to be lightweight and 
>> using copies allows temporary property maps to be passed in.
>> 
> I don't understand this. If I have a graph of one million vertices and even 
> more edges, the property map (e.g. defining something for each vertex) is 
> certainly not lightweight. Or do you mean other property maps?

The property map is not intended to own the data; thus, copying a property 
map is only a shallow copy and thus cheap.  That is why classes such as 
iterator_property_map require a separate object for the actual data 
storage; that object is not copied when the property map is copied.

-- Jeremiah Willcock