On Thu, 24 Jun 2010, W.P. McNeill wrote:
Thanks for your help. Getting a little closer. Once I get the edge properties working I'll look at traversal concepts other than AdjacencyGraphs. So far this has been the easy part for me.
I have been looking at the grid graph, but I couldn't figure out how to add weights to the edges of a grid graph. I can't find a simple example of an implicit graph with properties. (Which is why I'm trying to write one now.)
What do you mean by "Write an empty struct that inherits from all of the ones that you are going to model"? I didn't think there were concept base classes to inherit from.
Changing the property typedef in the implicit graph struct to
typedef boost::property<boost::edge_weight_t, float> edge_property_type;
making the get() functions take constant graph object references, and checking against the ReadablePropertyGraphConcept improves the compilation. I now no longer have pages of errors, which makes me think I'm on the right track.
I still have two errors, both of which I'm confused about.
1. graph_concepts.hpp:390: error: conversion from ‘EdgeWeightMap’ to non-scalar type ‘boost::typed_identity_property_map<size_t>’ requested
This is the same as before. This error makes me feel like I've got the wrong return value for one of my get() functions, but after double-checking they look right.
That does seem odd; could you please send the full error message list (including instantiation stacks)?
2. property_map.hpp:318: error: no match for ‘operator[]’ in ‘(const boost::typed_identity_property_map<size_t>&)((const boost::typed_identity_property_map<size_t>*)(& pa))[k]’
I didn't think any concept required operator[], so I'm not sure why this is happening. Line 318 is inside the inline get() function of the put_get_helper(), but I'm not using put_get_helper() in my code.
This is probably from the same confusion that triggered the previous error; it looks like one of the concept checks is testing against MutableLvaluePropertyMapConcept (which does require operator[]), but I can't tell why off-hand. -- Jeremiah Willcock