Hi, Boost Geometry 1.78, linux  I was getting bad results with my calculations so I decided to narrow down the implementation up to the point I got the following problematic code:  typedef boost::geometry::model::point Vector2d;  int main (){         multi_polygon mp;         /*{                polygon <Vector2d> poly;                 poly.outer().push_back( {0, 0} );                poly.outer().push_back( {0, 4} );                poly.outer().push_back( {4, 4} );                poly.outer().push_back( {4, 0} );                 correct( poly );                 mp.push_back(poly);        }*/        {                polygon <Vector2d> poly;                 poly.outer().push_back( {10, -1} );                poly.outer().push_back( {14, -1} );                poly.outer().push_back( {10, -2} );                poly.outer().push_back( {14, -2} );                 correct( poly );                 mp.push_back(poly);        }          boost::geometry::strategy::buffer::join_miter join_strategy;        boost::geometry::strategy::buffer::end_flat end_strategy;        boost::geometry::strategy::buffer::side_straight side_strategy;        boost::geometry::strategy::buffer::point_square point_strategy;         boost::geometry::strategy::buffer::distance_symmetric <double> distance_strategy( 2 );        boost::geometry::model::multi_polygon result;         boost::geometry::buffer( mp, result, distance_strategy, side_strategy, join_strategy, end_strategy, point_strategy );         cout << dsv( result ) << endl;         return 0;  }  and the result I get is: ((((13.7169, -3.13232), (13.5149, -3.94029), (12, -3.56155), (10.4851, -3.94029), (10.2831, -3.13232), (9.51493, -2.94029), (0.0749244, 0.221833), (10, 1), (14, 1), (23.9251, 0.221833), (14.4851, -2.94029), (13.7169, -3.13232))))  Notice the two points: (0.0749244, 0.221833) and (23.9251, 0.221833)  I have multiple complex (concave) shapes which behave worse than that simple rectangle. But it is a starting point here.  Did I do something wrong? I need to get my job done, any alternative or helping code massaging ?  Thanks -- MKL Â