https://svn.boost.org/trac10/ticket/12197 <p> The following code: </p> <pre class="wiki">typedef boost::geometry::model::polygon&lt;Point&gt; Polygon; typedef boost::geometry::model::multi_polygon&lt;Polygon&gt; MultiPolygon; Polygon outer1{ { { 2753.82399, 22518.895 }, { 2790.93453, 22448.2618 }, { 14793.2302, 27809.5376 }, { 14590.7789, 28141.4075 }, { 16120.2042, 25634.299 }, { 16830.1157, 23682.3504 }, { 3698, 17280.4245 }, { 3698, 20053 }, { 3290.86756, 20924.5835 }, { 3140.68998, 21523.9236 }, { 2753.82399, 22518.895 } } }; Polygon outer2{ { { -4891.23816, 18463.1873 }, { -5184.20528, 17101.1945 }, { -5793.67689, 15410.9396 }, { -6670.90183, 13924.6072 }, { -7655.52041, 12671.2939 }, { -8707.48466, 11854.286 }, { -9810.20847, 11342.7777 }, { -11002.6639, 11255.3896 }, { -12121.6054, 11341.764 }, { -13226.5153, 11854.286 }, { -14278.4796, 12671.2939 }, { -14967.9231, 13548.8837 }, { -4891.23816, 18463.1873 } } }; Polygon outer3{ { { -15799.8356, 25348.5883 }, { -15939.2155, 25634.3426 }, { -14410.8012, 28141.3084 }, { -12165.7175, 30390.1272 }, { -9561.60646, 32349.5454 }, { -6622.17286, 33700.601 }, { -3329.74574, 34602.3629 }, { -0.657491358, 34754.8041 }, { 3511.98218, 34602.0035 }, { 3199.23919, 34615.6034 }, { -15799.8356, 25348.5883 } } }; MultiPolygon multiPolygon; multiPolygon.push_back(outer1); multiPolygon.push_back(outer2); multiPolygon.push_back(outer3); std::cout &lt;&lt; (boost::geometry::is_valid(outer1) ? "outer1 is valid" : "outer1 is invalid") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::is_valid(outer2) ? "outer2 is valid" : "outer2 is invalid") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::is_valid(outer3) ? "outer3 is valid" : "outer3 is invalid") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::intersects(outer1, outer2) ? "1 and 2 intersects" : "1 and 2 do not intersects") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::intersects(outer1, outer3) ? "1 and 3 intersects" : "1 and 3 do not intersects") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::intersects(outer3, outer2) ? "3 and 2 intersects" : "3 and 2 do not intersects") &lt;&lt; std::endl; boost::geometry::validity_failure_type failure; auto test = boost::geometry::is_valid(multiPolygon, failure); std::cout &lt;&lt; (test ? "multiPolygon is valid " : "multiPolygon is invalid ") &lt;&lt; failure &lt;&lt; std::endl; </pre><p> will fail (and show error code 21), but keep the same values, shorten every number by a few decimals, and all of a sudden, is_valid starts working again </p> <pre class="wiki">typedef boost::geometry::model::polygon&lt;Point&gt; Polygon; typedef boost::geometry::model::multi_polygon&lt;Polygon&gt; MultiPolygon; Polygon outer1{ { {2753.82, 22518.9}, {2790.93, 22448.3}, {14793.2, 27809.5}, {14590.8, 28141.4}, {16120.2, 25634.3}, {16830.1, 23682.4}, {3698, 17280.4} , {3698, 20053} , {3290.87, 20924.6}, {3140.69, 21523.9}, {2753.82, 22518.9} } }; Polygon outer2{ { {-4891.24, 18463.2}, {-5184.21, 17101.2}, {-5793.68, 15410.9}, {-6670.9, 13924.6} , {-7655.52, 12671.3}, {-8707.48, 11854.3}, {-9810.21, 11342.8}, {-11002.7, 11255.4}, {-12121.6, 11341.8}, {-13226.5, 11854.3}, {-14278.5, 12671.3}, {-14967.9, 13548.9}, {-4891.24, 18463.2} } }; Polygon outer3{ { {-15799.8, 25348.6}, {-15939.2, 25634.3}, {-14410.8, 28141.3}, {-12165.7, 30390.1}, {-9561.61, 32349.5}, {-6622.17, 33700.6}, {-3329.75, 34602.4}, {-0.657491, 34754.8}, {3511.98, 34602}, {3199.24, 34615.6}, {-15799.8, 25348.6} } }; MultiPolygon multiPolygon; multiPolygon.push_back(outer1); multiPolygon.push_back(outer2); multiPolygon.push_back(outer3); std::cout &lt;&lt; (boost::geometry::is_valid(outer1) ? "1 is valid" : "1 is invalid") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::is_valid(outer2) ? "2 is valid" : "2 is invalid") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::is_valid(outer3) ? "3 is valid" : "3 is invalid") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::intersects(outer1, outer2) ? "1 and 2 intersects" : "1 and 2 do not intersects") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::intersects(outer1, outer3) ? "1 and 3 intersects" : "1 and 3 do not intersects") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::intersects(outer3, outer2) ? "3 and 2 intersects" : "3 and 2 do not intersects") &lt;&lt; std::endl; std::cout &lt;&lt; (boost::geometry::is_valid(multiPolygon) ? "multiPolygon is valid" : "multiPolygon is invalid") &lt;&lt; std::endl; </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/12197 Trac 1.4.3 John Maddock Mon, 16 May 2016 17:57:49 GMT https://svn.boost.org/trac10/ticket/12197#comment:1 https://svn.boost.org/trac10/ticket/12197#comment:1 <ul> <li><strong>owner</strong> set to <span class="trac-author">Barend Gehrels</span> </li> <li><strong>component</strong> <span class="trac-field-old">None</span> → <span class="trac-field-new">geometry</span> </li> </ul> Ticket