Dear Sir/Madam, Many thanks for your work on boost library. I am a user of the library. But now I meet a problem regarding to the function intersection. Could you please see the attached file. When I get the intersection of the polygon "red" and "blue" with the function, the output is the "green" (only one polygon). However, "green" should be two polygons. And if the green is regarded as one polygon, there is some error to get the intersection of it with others. That means I cannot calculate the intersection of "green" and "blue" with intersection(). The error is as following: This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. terminate called after throwing an instance of 'boost::geometry::overlay_invalid_input_exception' what(): Boost.Geometry Overlay invalid input exception All the best -- Dr.-Ing. Jun Zhang Jülich Supercomputing Centre Institute for Advanced Simulation phone +49 2461 61 1995 E-Mail: ju.zhang@fz-juelich.de<mailto:ju.zhang@fz-juelich.de> Internet: http://www.fz-juelich.de/ias/jsc ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDir Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------