C++ template specialization by type groups combined with basic type

Question

I would like to specialize template by group of types and also by extra definition for some specific simple types. Is it in C++11 and boost 1.60 possible? Following pseudocode illustrates my intention:

template <typename T> // Universal definition
struct convert
{  ...  }

template <> /* Definition for integral types like defined by std::type_traits */
struct convert<integral_types>
{  ...  }

template <> /* Definition for floating point types like defined by type_traits */
struct convert<floating_types>
{  ...  }

template <> /* Exception from integral types - specific definition */
struct convert<char>
{  ...  }

I think this could be solved by tag dispatcher, but I'm not sure if it's best solution. Another option is enable_if, combined with is_integral (and similar groups) , but simple char type is problem...

Answer 1

You may do something like:

template <typename T, typename Enabler = void> // Universal definition
struct convert
{  ...  };

template <typename T> /* Definition for integral types like defined by std::type_traits */
struct convert<T, std::enable_if_t<std::is_integral<T>::value>>
{  ...  };

template <> /* Exception from integral types - specific definition */
struct convert<char, void>
{  ...  };