Re: [Boost-users] newbie - graph library - vertex properties

15 Dec 2009

      Hi again,

Try the following code, which just compiles fine with g++ 4.4.1 on my 
system:

struct City{...};
struct Highway{...};

typedef ... Map;

int main(){
Map map;
Map::vertex_descriptor v = add_vertex( map );
Map::vertex_descriptor u = add_vertex( map );
map[v].name = "Troy";
map[v].population = 49170;
map[v].zipcodes.push_back(12180);
Map::edge_descriptor e = add_edge( u, v, map ).first;
map[e].name = "I-87";
map[e].miles = 10;
map[e].speed_limit = 65;
map[e].lanes = 4;
map[e].divided = true;
return 0;
}

Generally I would suggest reading
http://www.boost.org/doc/libs/1_41_0/libs/graph/doc/quick_tour.html
which gives a quick overview of how to handle graphs in BGL.

If you work through this tutorial, vertex and edge properties will also 
get explained.

Regards
Tobias

On Tuesday 15 December 2009 05:00:01 pm List User wrote:
...
Hi Tobias Columbus,
In fact I had tried that also. But then I got a funny message while 
executing like this: Ubuntu 9.04, g++ 4.3.3
//Map::vertex_descriptor v = *vertices(map).first;
 Map::vertex_descriptor v = add_vertex(map);
suresh@suresh-laptop:~/C++$ ./a.out 
*** glibc detected *** ./a.out: free(): invalid pointer: 0x09f9c064

...
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0xb7e6a604]
/lib/tls/i686/cmov/libc.so.6(cfree+0x96)[0xb7e6c5b6]
/usr/lib/libstdc++.so.6(_ZdlPv+0x21)[0xb804d231]
../a.out[0x8049e7d]
../a.out[0x8049ea7]
..
..
..
so what to do next?
suresh