Compilation error with polygon and multi_array

[voodooattack@…]

With this piece of code:

#include <boost/multi_array.hpp>
#include <boost/polygon/polygon.hpp>

int main()
{
	typedef boost::polygon::polygon_45_with_holes_data<int> polygon;
	typedef boost::polygon::polygon_traits<polygon>::point_type point;
	
	point centroid;
	polygon poly;
	
	boost::polygon::center(c.centroid, c.poly);
}

If you include the headers in the following order:

#include <boost/multi_array.hpp>
#include <boost/polygon/polygon.hpp>

..it breaks, if you reverse them it works:

#include <boost/polygon/polygon.hpp>
#include <boost/multi_array.hpp>

[anonymous]

The compilation error is:

/usr/local/include/boost/polygon/polygon_traits.hpp:1429:26: error: no match for call to ‘(boost::multi_array_types::extent_gen {aka boost::detail::multi_array::extent_gen<0ul>}) (boost::polygon::rectangle_data<int>&, const boost::polygon::polygon_45_with_holes_data<int>&)’

[Andrii Sydorchuk]

The problem here is with ADL (argument dependent lookup). The issues is explained with an example here: ​http://stackoverflow.com/questions/2958648/what-are-the-pitfalls-of-adl. From what I understood, there is no way to fix this permanently, as I can not rename the Boost.Polygon method because it's part of the public interface. The possible solution will be to use the following directive at the top of your file: #define BOOST_MULTI_ARRAY_NO_GENERATORS 1

[Andrii Sydorchuk]

I am marking the issue as "wontfix", as it requires the changes to the C++ standard. Here is some additional reading from Dave Abrahams: ​http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3490.html

[Andrii Sydorchuk]

I've found the way to fix the issue by changing the order of method definitions inside the Polygon library. Please use the attached patch.