The following is the declaration of the property merge algorithm.
coordinate_type, typename property_type>
The property algorithm computes the n-layer map overlay of input polygon sets. Each input geometry is inserted along with a property value. The property type can be anything suitable for use as an element of a std::set. Multiple geometry objects can be separately inserted with the same property value. To store the result of this operation a fairly complex container is required. Resulting geometries are associated with unique subsets of property values of the input geometry. Two suitable containers for storing the result of a property merge operation are:
Example code property_merge_usage.cpp demonstrates using the n-layer map-overlay algorithm on polygon data.