Jason Sachs wrote:

does anyone have a simple example of a map in shared memory, where the key is also in shared memory & not a simple "int"?

This example will go in the "quick guide for the impatient" section ASAP. ////////////////////////////////////////////////////////////////////////////// // // (C) Copyright Ion Gaztanaga 2006-2008. Distributed under 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) // // See http://www.boost.org/libs/interprocess for documentation. // ////////////////////////////////////////////////////////////////////////////// #include #include //[doc_complex_map #include #include #include #include #include using namespace boost::interprocess; //Typedefs of allocators and containers typedef managed_shared_memory::segment_manager segment_manager_t; typedef allocator void_allocator; typedef allocator int_allocator; typedef vector int_vector; typedef allocator int_vector_allocator; typedef vector int_vector_vector; typedef allocator char_allocator; typedef basic_string char_string; class complex_data { int id_; char_string char_string_; int_vector_vector int_vector_vector_; public: //Since void_allocator is convertible to any other allocator<T>, we can simplify //the initialization taking just one allocator for all inner containers. complex_data(int id, const char *name, const void_allocator &void_alloc) : id_(id), char_string_(name, void_alloc), int_vector_vector_(void_alloc) {} //Other members... }; //Definition of the map holding a string as key and complex_data as mapped type typedef std::pair map_value_type; typedef std::pair movable_to_map_value_type; typedef allocator map_value_type_allocator; typedef map< char_string, complex_data , std::less, map_value_type_allocator> complex_map_type; int main () { shared_memory_object::remove("MySharedMemory"); remove_shared_memory_on_destroy remove_on_destroy("MySharedMemory"); { //Create shared memory managed_shared_memory segment(create_only,"MySharedMemory", 65536); //An allocator convertible to any allocator type void_allocator alloc_inst (segment.get_segment_manager()); //Construct the shared memory map and fill it complex_map_type *mymap = segment.construct //(object name), (first ctor parameter, second ctor parameter) ("MyMap")(std::less(), alloc_inst); for(int i = 0; i < 100; ++i){ //Both key(string) and value(complex_data) need an allocator in their constructors char_string key_object(alloc_inst); complex_data mapped_object(i, "default_name", alloc_inst); map_value_type value(key_object, mapped_object); //Modify values and insert them in the map mymap->insert(value); } } return 0; } //] #include