There are two type is_foo_type functor For example is_double can be --------- template<typename T> struct is_double_template : boost::is_same<T,double> {}; --------- or --------- struct is_double_runtime { template<typename T> bool operator()(T x){return false;} bool operator()(double x){return true;} }; --------- Are there any standard naming rule distinguish these functor? is_foo_runtime is_foo_compiletime ? The compile-time functor can convert to runtime factor using : --------- template<typename IsTemplateMplLambda> struct is_templated_type_to_runtime { typedef struct is_templated_type_runtime { template<typename T> bool operator()(T) { return boost::mpl::apply<IsTemplateMplLambda,T>::type::value; } } type; }; --------- usage --------- typedef boost::mpl::lambda<is_double_template<boost::mpl::_1 >
::type is_double_mpl_lambda;
double x=1.1; int i=2; is_templated_type_to_runtime<is_double_mpl_lambda>::type is_double_runtime_object; std::cout << is_double_runtime_object(x) << std::endl; std::cout << is_double_runtime_object(i) << std::endl; ---------