[Question/Issue] Add named vertex does not work proper

[DwarKapex]

Hi guys!

I'm studying BGL now and I found a tutorial for it. Everything worked fine from it until I reached function to add_named_vertex. Here is a piece of code I have, that does not work as I (and tutorial) expect:

#include <boost/graph/graphviz.hpp>
#include <type_traits>
#include <iostream>
#include <sstream>
#include <string>

boost::adjacency_list<
    boost::vecS,
    boost::vecS,
    boost::directedS,
    boost::property<boost::vertex_name_t, std::string>
>
create_empty_graph() { return {}; }

template<typename graph, typename name_type>
typename boost::graph_traits<graph>::vertex_descriptor
add_named_vertex(const name_type& vertex_name, graph& g) noexcept {
    const auto vd = boost::add_vertex(g);
    auto vertex_name_map = get(boost::vertex_name, g);
    put(vertex_name_map, vd, vertex_name);
    return vd;
}

int main()
{
    auto g = create_empty_graph();
    const auto va = add_named_vertex("One", g);
    const auto vb = add_named_vertex("Two", g);
    boost::add_edge(va,vb, g);

    std::stringstream f;
    boost::write_graphviz(f, g);
    std::cout << f.str() << std::endl;
    
    return 0;
}

I expect:

digraph G {
0[label=One];
1[label=Two];
0->1;
}

But here is what I got:

digraph G {
0;
1;
0->1;
}

As you can see, there are no labels in the output of this code. Could you please tell me, what am I missing? Is it expected behavior?

Thanks you very much in advance for your great work!

[jeffythedragonslayer]

I'm not sure, I've used a std::map<vertex_t, std::string> in the past as a workaround.

[DwarKapex]

@jeffythedragonslayer can you provide a code snippet for that? =) And if you know a good tutorial for boost graph library, I would be more then appreciated for it!

[jeffythedragonslayer]

https://github.com/jeffythedragonslayer/lipton-tarjan checkout e92e73ac2e6c295858f59372ecd35683e3d78297 it's the last commit before I deleted it :o See Vert2UintMap.{h, cpp} Replace the uints with strings and there you go :)

I'm actually working on a ppt presentation/talk on understanding the boost graph library for CppMaryland at the moment as everything I found at the time of starting that project was unrelentingly dense. (Here's an example: https://github.com/richelbilderbeek/BoostGraphTutorial/blob/master/boost_graph_tutorial.pdf)