Here is a list of all namespaces with brief descriptions:

[detail level 12]

argagg	There are only two hard things in Computer Science: cache invalidation and naming things (Phil Karlton)
convert	The set of template instantiations that convert C-strings to other types for the option_result::as(), option_results::as(), parser_results::as(), and parser_results::all_as() methods are placed in this namespace
std	STL namespace