Re: [Boost-users] [BGL] resize/reserve on graph?

Subject: Re: [Boost-users] [BGL] resize/reserve on graph?
From: Anil Ramapanicker (anilpanicker_at_[hidden])
Date: 2011-08-09 19:29:07

I did not get you properly, I'm suggesting to replace std::vector with
boost::vector_property_map
that can hold variable number of elements
Anil

On Tue, Aug 9, 2011 at 6:59 PM, Geoff Hilton <geoff.hilton_at_[hidden]>wrote:

> On Tue, Aug 9, 2011 at 3:13 PM, Geoff Hilton
>> <geoff.hilton_at_[hidden] <mailto:geoff.hilton_at_t-**optlogic.com<geoff.hilton_at_[hidden]>>>
>> wrote:
>>
>>    If I know that during the execution of the algorithm the graph size
>>    must be grown by X number of vertices in one go, is there a way this
>>    can be done to avoid multiple allocations such as when using
>>    std::vector's reserve(..) or resize(..) member functions without
>>    subverting the BGL's documented interface? Currently I use a for
>>    loop which iterates over add_vertex(vertex_property, graph). Can a
>>    reserve and/or resize equivalent otherwise please be added somewhere?
>>
>>    Thank you,
>>    Geoff
>>
>
> > On 09/08/2011 6:12 PM, Anil Ramapanicker wrote:
> > I think you are asking about implicit graph where vertices and edges are
> > unknown at the begining and they are added during the execution of an
> > algorithm. You can do it in two ways
> > a) If you are using internal properties then
> > add_vertex( vertex_whatever,g) will work
> > b) If you are using exterior property map then use vector_property_map
> > since the size is unknown
> > http://www.boost.org/doc/libs/**1_47_0/libs/property_map/doc/**
> vector_property_map.html<http://www.boost.org/doc/libs/1_47_0/libs/property_map/doc/vector_property_map.html>
> > Anil
>
> That's exactly what I'm already doing. I'm asking because true, at first I
> do invariably have to use add_vertex(..), but later on I know exactly how
> many vertices by which to grow the graph at a time due to the algorithm I'm
> implementing and I wish to add them in as few memory allocations as possible
> (preferably one) to the existing graph. Thus, something like std::vector's
> resize/reserve or an equivalent would be useful.
>
>
> Thank you,
> Geoff
>
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