[Boost-users] [parameter] requirement const char*

From: Jean-Christophe Roux (jcxxr_at_[hidden])
Date: 2007-09-26 16:54:32

Hello,

Thank you for the parameter library; it is making my library much nicer 
to use. Two questions:
1. I am assuming there is no runtime penalty to use the BOOST_PARAMETER 
version of a function. Is that right?
2. My code looks like that:
namespace keywords
{
   BOOST_PARAMETER_NAME(id)
   BOOST_PARAMETER_NAME(test)
}
BOOST_PARAMETER_FUNCTION
(
   (void),foo,keywords::tag, (optional (id, *, "")
                                       (test, (const char*), "")
                             )
)
{
     ...
}
   Here the parameters must be converted, if necessary, to const char* 
in order to be used later. What would be the best way to write the 
requirement that the type must be const char* or must be convertible to 
const char*?
thanks for your help