On Thu, Mar 7, 2013 at 8:57 PM, Niitsuma Hirotaka < hirotaka.niitsuma@gmail.com> wrote:

There are two type is_foo_type functor For example is_double can be

--------- template<typename T> struct is_double_template : boost::is_same {}; ---------

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?

I don't think so, but reasonable alternatives are: - Name them the same thing (union the above definitions). - Name the structs the same, but put them in different namespaces (e.g., mpl and functional). - Name them static_foo and foo (this is the convention used by Boost.Math, I think, for integer functions). 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::type::value; } } type; };

Oh, so then what do you need the runtime foo one for? :) - Jeff

2013/3/8 Niitsuma Hirotaka :

There are two type is_foo_type functor For example is_double can be

--------- template<typename T> struct is_double_template : boost::is_same {}; ---------

or

--------- struct is_double_runtime { template<typename T> bool operator()(T x){return false;} bool operator()(double x){return true;} };

Why don't you just use BOOST_TYPEOF(x) macro? T d; std::cout << is_double<T>::value << std::endl; std::cout << is_double::value << std::endl; -- Best regards, Antony Polukhin