[/============================================================================
  Boost.Geometry Index

  Copyright (c) 2011-2014 Adam Wulkiewicz.

  Use, modification and distribution is subject to the Boost Software License,
  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  http://www.boost.org/LICENSE_1_0.txt)
=============================================================================/]

 filling index with polygons shared pointers:
 POLYGON((1 0,0.4 0.8,-0.5 0.8,-0.9 0,-0.4 -0.8,0.5 -0.8,1 0))
 POLYGON((2 1,1.4 1.8,0.5 1.8,0.1 1,0.6 0.2,1.5 0.2,2 1))
 POLYGON((3 2,2.4 2.8,1.5 2.8,1.1 2,1.6 1.2,2.5 1.2,3 2))
 POLYGON((4 3,3.4 3.8,2.5 3.8,2.1 3,2.6 2.2,3.5 2.2,4 3))
 POLYGON((5 4,4.4 4.8,3.5 4.8,3.1 4,3.6 3.2,4.5 3.2,5 4))
 POLYGON((6 5,5.4 5.8,4.5 5.8,4.1 5,4.6 4.2,5.5 4.2,6 5))
 POLYGON((7 6,6.4 6.8,5.5 6.8,5.1 6,5.6 5.2,6.5 5.2,7 6))
 POLYGON((8 7,7.4 7.8,6.5 7.8,6.1 7,6.6 6.2,7.5 6.2,8 7))
 POLYGON((9 8,8.4 8.8,7.5 8.8,7.1 8,7.6 7.2,8.5 7.2,9 8))
 POLYGON((10 9,9.4 9.8,8.5 9.8,8.1 9,8.6 8.2,9.5 8.2,10 9))
 spatial query box:
 POLYGON((0 0,0 5,5 5,5 0,0 0))
 spatial query result:
 POLYGON((1 0,0.4 0.8,-0.5 0.8,-0.9 0,-0.4 -0.8,0.5 -0.8,1 0))
 POLYGON((2 1,1.4 1.8,0.5 1.8,0.1 1,0.6 0.2,1.5 0.2,2 1))
 POLYGON((3 2,2.4 2.8,1.5 2.8,1.1 2,1.6 1.2,2.5 1.2,3 2))
 POLYGON((4 3,3.4 3.8,2.5 3.8,2.1 3,2.6 2.2,3.5 2.2,4 3))
 POLYGON((5 4,4.4 4.8,3.5 4.8,3.1 4,3.6 3.2,4.5 3.2,5 4))
 POLYGON((6 5,5.4 5.8,4.5 5.8,4.1 5,4.6 4.2,5.5 4.2,6 5))
 knn query point:
 POINT(0 0)
 knn query result:
 POLYGON((5 4,4.4 4.8,3.5 4.8,3.1 4,3.6 3.2,4.5 3.2,5 4))
 POLYGON((4 3,3.4 3.8,2.5 3.8,2.1 3,2.6 2.2,3.5 2.2,4 3))
 POLYGON((3 2,2.4 2.8,1.5 2.8,1.1 2,1.6 1.2,2.5 1.2,3 2))
 POLYGON((1 0,0.4 0.8,-0.5 0.8,-0.9 0,-0.4 -0.8,0.5 -0.8,1 0))
 POLYGON((2 1,1.4 1.8,0.5 1.8,0.1 1,0.6 0.2,1.5 0.2,2 1))