使用自定义获取属性提升动态属性

Question

I am trying to use boost::dynamic properties to multiple properties to the Graphviz output.

I am familiar with custom property writer ( How to print a graph in graphviz with multiple properties displayed ), but I am trying to do the same thing with dynamic properties. How do we write the above edge property writer using the dynamic properties in the following code? I want to write if else statements on the values of the weight and capacity as in if(weight <5 && capacity <5) then color = red and so on.

boost::dynamic_properties dp/*(ignore_other_properties)*/;
dp.property("node_id", get(&vert::name, g));
dp.property("color", get(??,g));
write_graphviz_dp(std::cout, g, dp);

Answer 1

See some options here: map set/get requests into C++ class/structure changes

You can either transform the result of one property map, or you can use a functional property map altogether.

Transforming values:

An example of using dynamic properties to transform a color property is here: Manually colouring of boost's graphs

Functional map:

• How to use boost::graph dijkstra's algorithm if vertex properties are pointers?
• My preference would be to use a member function and bind it using the transform_value_property_map as shown above, eg Using boost graph library with a custom class for vertices
• But here is an example using function_property_map as well boost dijkstra_shortest_paths: can't extract (or find?) the path (path contains a cycle)

Note that you also have make_constant_property_map (eg Boost Dynamic Properties with Custom get property )