Rene Rivera <grafik.list@redshift-software.com> writes:
Peter Dimov wrote:
Rene Rivera wrote: [...]
#include <boost/named_params.hpp>
struct name_t; // tag types struct value_t;
namespace { boost::keyword<name_t> name; // keyword objects boost::keyword<struct name_t> name; is even better. ;-)
Yes it is :-) -- But I was going under the suggestion in the docs:
[Note: the tag types should generally not be declared in an unnamed namespace]
It would be nice to see a rational for that note in the docs. Only one I can think of is the increased number of keyword objects, and possibly increased number of the function instantiations.
It's an ODR thing. If you then use the parameter names in a function template that's not in an unnamed namespace but _is_ in multiple TU's, you have technically violated the ODR. In general, types in header files had better stay out of the unnamed namespace. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com