RE: An internal add_const_reference type trait
Eric Lemings wrote:
>
>Travis Vitek wrote:
>>
>> >Eric Lemings wrote:
>> >
>> >Travis,
>> >
>> >According to our plans for type traits, is this how you
>> would define an
>> >internal class template that combines the add_const and
>> >add_reference type modifiers?
>> >
>> >#include
>> >
>> >_RWSTD_NAMESPACE (__rw) {
>> >
>> >template
>> >class __rw_add_const_ref
>> >{
>> >typedef _TYPENAME __rw_add_const<_TypeT>::type _ConstT;
>> >
>> >public:
>> >
>> >typedef _TYPENAME __rw_add_reference<_ConstT>::type type;
>> >};
>> >
>> >} // namespace __rw
>> >
>>
>> It is really close. I'd probably make it a struct and if
>there was any
>> complicated logic it would move into an impl struct to reduce
>> clutter in
>> the outer class.
>>
>> If you need the above trait, I should let you know that TR1 had
>> add_reference, but C++0x replaces that with add_lvalue_reference and
>> add_rvalue_reference. So it you should probably use the new
>> names as we
>> probably won't have an __rw_add_reference trait.
>>
>> #include
>>
>> _RWSTD_NAMESPACE (__rw) {
>>
>> template
>> struct __rw_add_const_ref
>> {
>> typedef _TYPENAME __rw_add_lval_ref<
>> _TYPENAME __rw_add_const<_TypeT>::type
>> >::type type;
>> };
>>
>> } // namespace __rw
>
>Actually, wouldn't this be even better?
>
> template
> struct __rw_add_const_ref
> : __rw_add_lval_ref<_RWSTD_ADD_CONST(_TypeT)> { };
>
Ah yes, assuming that I continue to provide the macros. :)
>Brad.
>
RE: An internal add_const_reference type trait
> -Original Message-
> From: Travis Vitek [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, June 10, 2008 10:34 AM
> To: dev@stdcxx.apache.org
> Subject: RE: An internal add_const_reference type trait
>
>
>
> >Eric Lemings wrote:
> >
> >Travis,
> >
> >According to our plans for type traits, is this how you
> would define an
> >internal class template that combines the add_const and
> >add_reference type modifiers?
> >
> > #include
> >
> > _RWSTD_NAMESPACE (__rw) {
> >
> > template
> > class __rw_add_const_ref
> > {
> > typedef _TYPENAME __rw_add_const<_TypeT>::type _ConstT;
> >
> > public:
> >
> > typedef _TYPENAME __rw_add_reference<_ConstT>::type type;
> > };
> >
> > } // namespace __rw
> >
>
> It is really close. I'd probably make it a struct and if there was any
> complicated logic it would move into an impl struct to reduce
> clutter in
> the outer class.
>
> If you need the above trait, I should let you know that TR1 had
> add_reference, but C++0x replaces that with add_lvalue_reference and
> add_rvalue_reference. So it you should probably use the new
> names as we
> probably won't have an __rw_add_reference trait.
>
> #include
>
> _RWSTD_NAMESPACE (__rw) {
>
> template
> struct __rw_add_const_ref
> {
> typedef _TYPENAME __rw_add_lval_ref<
> _TYPENAME __rw_add_const<_TypeT>::type
> >::type type;
> };
>
> } // namespace __rw
Actually, wouldn't this be even better?
template
struct __rw_add_const_ref
: __rw_add_lval_ref<_RWSTD_ADD_CONST(_TypeT)> { };
Brad.
RE: An internal add_const_reference type trait
>Eric Lemings wrote:
>
>Travis,
>
>According to our plans for type traits, is this how you would define an
>internal class template that combines the add_const and
>add_reference type modifiers?
>
> #include
>
> _RWSTD_NAMESPACE (__rw) {
>
> template
> class __rw_add_const_ref
> {
> typedef _TYPENAME __rw_add_const<_TypeT>::type _ConstT;
>
> public:
>
> typedef _TYPENAME __rw_add_reference<_ConstT>::type type;
> };
>
> } // namespace __rw
>
It is really close. I'd probably make it a struct and if there was any
complicated logic it would move into an impl struct to reduce clutter in
the outer class.
If you need the above trait, I should let you know that TR1 had
add_reference, but C++0x replaces that with add_lvalue_reference and
add_rvalue_reference. So it you should probably use the new names as we
probably won't have an __rw_add_reference trait.
#include
_RWSTD_NAMESPACE (__rw) {
template
struct __rw_add_const_ref
{
typedef _TYPENAME __rw_add_lval_ref<
_TYPENAME __rw_add_const<_TypeT>::type
>::type type;
};
} // namespace __rw
>Also, it'd be nice if you jot down some of these plans for type traits
>on the C++0x Wiki ; e.g., header
>names, internal utilities, TODO work, etc. ;)
Yes, I know. Given that discussion on the topic has died down I could
actually document what we've arrived at.
>
>Thanks,
>Brad.
>
