Re: [boost] playing with a graph example...

From: Jeremy Siek (jsiek_at_[hidden])
Date: 2001-03-25 16:12:33

Hi Artur,

This is a compiler bug (see the BGL trouble shooting page), and I've given
up trying to find a way to make the 3 arg get() work on VC++. However,
there is a simple workaround:

get(get(vertex_first_name, g), 1) 

Don't worry about making copies of the property map object... that is
suppose to be a fast operation.

Cheers,
Jeremy

On Sun, 25 Mar 2001 artwisz_at_[hidden] wrote:

artwis> Hello again,
artwis> I am having some strange behaviour with VC++...
artwis> I am playing with the interior_property_map.cpp example. Wrote a 
artwis> simple function to illustrate the case:
artwis> 
artwis> template<class Graph>
artwis> void tryIt(const Graph& g)
artwis>    {
artwis>    typedef typename property_map<Graph, vertex_first_name_t>
artwis>        ::const_type NamePA;
artwis>    NamePA name = get(vertex_first_name, g);
artwis>    string nm = boost::get(vertex_first_name, g, 1);
artwis>    }
artwis> 
artwis> and invoke 
artwis>    tryIt(G);
artwis> from main(). This works. But then comment out
artwis>    //NamePA name = get(vertex_first_name, g);
artwis> and I get the (abbreviated somehow) errors below. I would like to use 
artwis> the 3 argument get without getting the copy of the map.
artwis> Perhaps my library version is too old ?... 
artwis> TIA,
artwis> 
artwis> Artur
artwis> 
artwis> e:\c++lib\boost\property_map.hpp(283) : error C2676: 
artwis> binary '[' : 'const struct 
artwis> boost::vec_adj_list_vertex_property_map<class 
artwis> boost::adjacency_list<...>,class boost::adjacency_list<...> const 
artwis> &,struct 
artwis> boost::property<enum vertex_first_name_t,class 
artwis> std::basic_string<char,struct std::char_traits<char>,class 
artwis> std::allocator<char> >,struct boost::no_property>,enum 
artwis> vertex_first_name_t>' does not define this operator or a conversion 
artwis> to a type acceptable
artwis>  to the predefined operator
artwis>         e:\c++lib\boost\graph\detail\adjacency_list.hpp(1439) : see 
artwis> reference to function template instantiation 'class 
artwis> std::basic_string<...> __cdecl boost::get(const struct boost::put_get_
artwis> at_helper<class std::basic_string<...>,struct 
artwis> boost::vec_adj_list_vertex_property_map<class 
artwis> boost::adjacency_list<...>,class boost::adjacency_list<...> const 
artwis> &,struct boost::property<...>,struct boost::no_property>,enum 
artwis> vertex_first_name_t> > &,const int &)' being compiled
artwis> 
artwis> 
artwis> 
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artwis> 

----------------------------------------------------------------------
 Jeremy Siek                        www: http://www.lsc.nd.edu/~jsiek/
 Ph.D. Candidate                  email: jsiek_at_[hidden]
 Univ. of Notre Dame         work phone: [phone]
----------------------------------------------------------------------