"Sohail Somani" writes:

Is the prescribed method for the parameter library thread safe?

// appears to modify global variables "graph", etc core::depth_first_search(( graph = 'G', visitor = 2, root_vertex = 3.5, index_map = "hello, world", color_map = false));

Don't worry; it's perfectly thread safe. No global variables are being modified. -- Dave Abrahams Boost Consulting www.boost-consulting.com