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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

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