referenceable type?, C++ (vc++)

Language: Layout:

//Microsoft (R) C/C++ Optimizing Compiler Version 19.00.23506 for x86

#include <iostream>
#include <type_traits>

namespace detail {

template < typename... > struct is_const_qualified : std::false_type {} ;
    template < typename R, typename... A > struct is_const_qualified< R(A...) const > : std::true_type {} ;
    template < typename R, typename... A > struct is_const_qualified< R( A..., ... ) const > : std::true_type {} ;

template < typename... > struct is_volatile_qualified : std::false_type {} ;
    template < typename R, typename... A > struct is_volatile_qualified< R(A...) volatile > : std::true_type {} ;
    template < typename R, typename... A > struct is_volatile_qualified< R( A..., ... ) volatile > : std::true_type {} ;

template < typename... > struct is_cv_qualified : std::false_type {} ;
    template < typename R, typename... A > struct is_cv_qualified< R(A...) const volatile > : std::true_type {} ;
    template < typename R, typename... A > struct is_cv_qualified< R( A..., ... ) const volatile > : std::true_type {} ;

template < typename... > struct is_ref_qualified : std::false_type {} ;

template < typename R, typename... A > struct is_ref_qualified< R(A...) & > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R(A...) && > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R(A...) const & > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R(A...) const && > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R(A...) volatile & > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R(A...) volatile && > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R(A...) const volatile & > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R(A...) const volatile && > : std::true_type {} ;

template < typename R, typename... A > struct is_ref_qualified< R( A..., ... ) & > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R( A..., ... ) && > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R( A..., ... ) const & > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R( A..., ... ) const && > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R( A..., ... ) volatile & > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R( A..., ... ) volatile && > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R( A..., ... ) const volatile & > : std::true_type {} ;
    template < typename R, typename... A > struct is_ref_qualified< R( A..., ... ) const volatile && > : std::true_type {} ;
}

template < typename T > struct is_referenceable
                            : std::conditional< detail::is_const_qualified<T>::value ||
                                                detail::is_volatile_qualified<T>::value ||
                                                detail::is_cv_qualified<T>::value ||
                                                detail::is_ref_qualified<T>::value,
                                                std::false_type, std::true_type >::type {} ;

template < typename T > void show_referenceability( const char* desc )
{
    std::cout << "type '" << desc << "' : referenceable? "
              << std::boolalpha << is_referenceable<T>::value << '\n' ;
}

#define SHOW_REFERENCEABILITY(T) show_referenceability<T>(#T)

int main()
{
    std::cout << "-------- referenceable types -------\n" ;

SHOW_REFERENCEABILITY(int) ;
    SHOW_REFERENCEABILITY( int(char,double,...) ) ;
    SHOW_REFERENCEABILITY(std::ostream) ;

std::cout << "-------- non-referenceable types -------\n" ;

SHOW_REFERENCEABILITY( int(char,double&,short&&) const ) ;
    SHOW_REFERENCEABILITY( int(char,double) volatile ) ;
    SHOW_REFERENCEABILITY( int() const volatile ) ;
    SHOW_REFERENCEABILITY( int(char) & ) ;
    SHOW_REFERENCEABILITY( int() volatile && ) ;
    SHOW_REFERENCEABILITY( int() const & ) ;
    SHOW_REFERENCEABILITY( int() const volatile && ) ;
    SHOW_REFERENCEABILITY( int( char, double, ... ) volatile ) ;
    SHOW_REFERENCEABILITY( int( char, ... ) & ) ;
    SHOW_REFERENCEABILITY( int(...) && ) ;
}

Show compiler warnings [ + ] Compiler args [ + ] Show input
Compilation time: 2,22 sec, absolute running time: 0,22 sec, absolute service time: 2,45 sec