I have a few questions about the parameter library. Please note that I am using argument packs directly, since I am creating them from another data structure. 1. Is there a way to build Boost.Parameter ArgumentPacks from a program? I am currently using many internal data structures of Boost.Parameter (empty_arg_list and such). Is there another interface to use? 2. Is there a way to tell at compile-time whether a particular parameter exists in an ArgumentPack? I currently have a metafunction that uses a special default type and tests for that; is there a more "official" way? 3. I have a case where the default type for a named parameter cannot be instantiated in some cases where that parameter is given explicitly. The operator||() lazy defaults don't seem to work for that because they get the result_type member from my default right away, even if it won't be used. I currently have a hack to work around this using my parameter_exists test and some metaprogramming. The reason I am working on this low of a level is that I am playing with converting Boost.Graph named parameter structures into ArgumentPacks to have access to Boost.Parameter's nicer capabilities and syntax. I thus need to build all of the argument data structures and such within another function and then access them later. Thank you for your help. -- Jeremiah Willcock