https://svn.boost.org/trac10/ticket/13494 <p> Hello, </p> <p> executing the following polygon intersection produces an empty result although the second operand is completely inside the first. </p> <p> Code snippet: </p> <blockquote> <p> using point_type = boost::geometry::model::d2::point_xy&lt;double&gt;; using polygon = boost::geometry::model::polygon&lt;point_type&gt;; using multi_polygon = boost::geometry::model::multi_polygon&lt;polygon&gt;; </p> </blockquote> <blockquote> <p> polygon op1, op2; multi_polygon result; </p> </blockquote> <p> </p> <blockquote> <p> boost::geometry::read_wkt("POLYGON((-1.99900000000000011 -0.889961757413527343,-1.99900000000000011 -1.12178395051169733,-1.89792526415373097 -1.49900000000000011,-1.8358086947169705 -1.49900000000000011,-1.99900000000000011 -0.889961757413527343))", op1); boost::geometry::read_wkt("POLYGON((-1.97591538973459313 -1.20793688888334905,-1.92415157993614439 -1.40112205701807624,-1.8661960316547388 -1.38559291465704759,-1.91795984145318754 -1.19240774652231996,-1.97591538973459313 -1.20793688888334905))", op2); boost::geometry::intersection(op1, op2, result); </p> </blockquote> <p> I could track down the problem to the intersection/touch part. We use the intersection code quite heavily and such a constellation can occur frequently in our application. (I could present several more sample data for this bug). Therefore I set this to showstopper. Also I found other entries which look quite similar. </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/13494 Trac 1.4.3