Type trait for copying cv reference qualifiers

Writing library-like code in C++ I found there is particular need in copy_cv_reference_t type trait:

struct A;
struct B;

static_assert(std::is_same< copy_cv_reference_t<          A         , B >,          B          >{});
static_assert(std::is_same< copy_cv_reference_t<          A const   , B >,          B const    >{});
static_assert(std::is_same< copy_cv_reference_t< volatile A         , B >, volatile B          >{});
static_assert(std::is_same< copy_cv_reference_t< volatile A const   , B >, volatile B const    >{});
static_assert(std::is_same< copy_cv_reference_t<          A        &, B >,          B        & >{});
static_assert(std::is_same< copy_cv_reference_t<          A const  &, B >,          B const  & >{});
static_assert(std::is_same< copy_cv_reference_t< volatile A        &, B >, volatile B        & >{});
static_assert(std::is_same< copy_cv_reference_t< volatile A const  &, B >, volatile B const  & >{});
static_assert(std::is_same< copy_cv_reference_t<          A       &&, B >,          B       && >{});
static_assert(std::is_same< copy_cv_reference_t<          A const &&, B >,          B const && >{});
static_assert(std::is_same< copy_cv_reference_t< volatile A       &&, B >, volatile B       && >{});
static_assert(std::is_same< copy_cv_reference_t< volatile A const &&, B >, volatile B const && >{});

I invent it for myself using two approaches: via means of id of type qualifiers and via SFINAE only.

#include <type_traits>

#if 1
enum class type_qual_id
{
    value,
    const_value,
    lref,
    const_lref,
    rref,
    const_rref,
    volatile_value,
    volatile_const_value,
    volatile_lref,
    volatile_const_lref,
    volatile_rref,
    volatile_const_rref,
};

template< type_qual_id tqid, typename type > struct add_type_qualifier;
template< typename to > struct add_type_qualifier< type_qual_id::value               , to > { using type =          to         ; };
template< typename to > struct add_type_qualifier< type_qual_id::const_value         , to > { using type =          to const   ; };
template< typename to > struct add_type_qualifier< type_qual_id::lref                , to > { using type =          to       & ; };
template< typename to > struct add_type_qualifier< type_qual_id::const_lref          , to > { using type =          to const & ; };
template< typename to > struct add_type_qualifier< type_qual_id::rref                , to > { using type =          to       &&; };
template< typename to > struct add_type_qualifier< type_qual_id::const_rref          , to > { using type =          to const &&; };
template< typename to > struct add_type_qualifier< type_qual_id::volatile_value      , to > { using type = volatile to         ; };
template< typename to > struct add_type_qualifier< type_qual_id::volatile_const_value, to > { using type = volatile to const   ; };
template< typename to > struct add_type_qualifier< type_qual_id::volatile_lref       , to > { using type = volatile to       & ; };
template< typename to > struct add_type_qualifier< type_qual_id::volatile_const_lref , to > { using type = volatile to const & ; };
template< typename to > struct add_type_qualifier< type_qual_id::volatile_rref       , to > { using type = volatile to       &&; };
template< typename to > struct add_type_qualifier< type_qual_id::volatile_const_rref , to > { using type = volatile to const &&; };

template< type_qual_id tqid, typename to >
using add_qualifier_t = typename add_type_qualifier< tqid, to >::type;

template< typename type > constexpr type_qual_id get_type_qualifier_id                           = type_qual_id::value               ;
template< typename type > constexpr type_qual_id get_type_qualifier_id<          type const    > = type_qual_id::const_value         ;
template< typename type > constexpr type_qual_id get_type_qualifier_id<          type       &  > = type_qual_id::lref                ;
template< typename type > constexpr type_qual_id get_type_qualifier_id<          type const &  > = type_qual_id::const_lref          ;
template< typename type > constexpr type_qual_id get_type_qualifier_id<          type       && > = type_qual_id::rref                ;
template< typename type > constexpr type_qual_id get_type_qualifier_id<          type const && > = type_qual_id::const_rref          ;
template< typename type > constexpr type_qual_id get_type_qualifier_id< volatile type          > = type_qual_id::volatile_value      ;
template< typename type > constexpr type_qual_id get_type_qualifier_id< volatile type const    > = type_qual_id::volatile_const_value;
template< typename type > constexpr type_qual_id get_type_qualifier_id< volatile type       &  > = type_qual_id::volatile_lref       ;
template< typename type > constexpr type_qual_id get_type_qualifier_id< volatile type const &  > = type_qual_id::volatile_const_lref ;
template< typename type > constexpr type_qual_id get_type_qualifier_id< volatile type       && > = type_qual_id::volatile_rref       ;
template< typename type > constexpr type_qual_id get_type_qualifier_id< volatile type const && > = type_qual_id::volatile_const_rref ;

template< typename from, typename to >
using copy_cv_reference_t = add_qualifier_t< get_type_qualifier_id< from >, to >;

#else
#include <type_traits>

template< typename from, typename to >
struct copy_cv
{

    using type = to;

};

template< typename from, typename to >
struct copy_cv< from const, to >
    : copy_cv< from, to const >
{

};

template< typename from, typename to >
struct copy_cv< volatile from, to >
    : copy_cv< from, volatile to >
{

};

template< typename from, typename to >
struct copy_cv< volatile from const, to >
    : copy_cv< from, volatile to const >
{

};

template< typename from, typename to >
struct copy_reference 
{

    using type = to;

};

template< typename from, typename to >
struct copy_reference< from &, to >
    : copy_reference< from, to & >
{

};

template< typename from, typename to >
struct copy_reference< from &&, to >
    : copy_reference< from, to && >
{

};

template< typename from, typename to >
using copy_cv_reference_t = typename copy_reference< from, typename copy_cv< std::remove_reference_t< from >, to >::type >::type;

#endif

First approach looks like something more artificial, but provides a "type qualifiers id" as additional side and latter can be useful in some situations. Second approach is inherently two-step one. It could has downsides. In addition, it involving std::remove_reference_t to reveal the cv-qualified type.

On the one hand, I know standard allows for implementations to have an "intrinsic" type traits. On the other hand, there is no the type trait currently in contemporary C++ standard.

What is the best implementation of copy_cv_reference_t type trait? Not only between above two. Are there better approaches to implement it? Is there corresponding proposal?

What about naming? What about order of ids?