Re: [Boost-users] [parameter]Boost Parameter and template template arguments

AMDG Jesse Perla wrote:

I have a class template with a large number of potential template parameters where I would like to use boost parameter. I understand that I can use integers with the int_<> wrapper, but is there any trick or design pattern to allow template template's? The problem is that I have class templates such as an interpolator which will take in a type and a dimension size, and a variety of function objects of the same type. If I can't use template templates, I am not sure how to make the design sane. For example, right now I have something like:

template template Interpolator = cubic_spline> class DPP;

I don't think I can write a free function to solve the instantiation difficulty since many of the types are only used internally and I couldn't use function template argument deduction.

Use mpl::lamdba expressions. First you need to wrap any templates that take non type template parameters. For example. template class make_cubic_spline { typedef cubic_spline type; }; Then, the default argument for Interpolator can be make_cubic_spline. When you need to get a real type, use mpl::apply: typedef boost::mpl::apply, double>::type interpolator_instance; In Christ, Steven Watanabe