🚀 go-pugleaf

"Howard Hinnant" <hinnant@metrowerks.com> skrev i melding
news:120220031147334006%hinnant@metrowerks.com...
> In article <b2dt3k$2g0n$1@news.dataguard.no>, Conrad Weyns
> <weyns@online.no> wrote:
>
> | "Miro Jurisic" <macdev@meeroh.org> skrev i melding
> | news:macdev-B2A383.10035512022003@senator-bedfellow.mit.edu...
> | > In article <b2dg2g$1117$1@news.dataguard.no>, "Conrad Weyns"
> | <weyns@online.no>
> | > wrote:
> | >
> | > > compiler: CW Pro 8.3 Mac & Win.
> | > > issue: how can I get hold of the real type name of T that is part of
a
> | > > function signature in the following stripped to the bone but working
> | code:
> | > >
> | > > Output of this running program:
> | > >
> | > > 1A. tA.report() gives:
> | > >    function name: _report<long>(long &)
> | > >    using __typeof__: long
> | > >    sWoes address: 0x00420460 sWoes = 999
> | > >    type of _t: long
> | > >    value of _t 123
> | > >
> | > > 2A. tA.const_report() gives:
> | > >    function name: _report<const long>(const long &)
> | > >    using __typeof__: long
> | > >    sWoes address: 0x00420454 sWoes = 999
> | > >    type of _t: long
> | > >    value of _t 123
> | >
> | > My understanding is that typeof (T) == typeof (const T) == typeof
> | (volatile T)
> | > == etc. Perhaps if you explain exactly what you are trying to do with
this
> | > information we can come up with an answer. (Which will involve type
> | traits, I am
> | > sure.)
> |
> | Thanks meeroh, looks like I need to go back to school -again :-(
> | Ehm, I am lying now, I never went to school!
> |
> | But this was the kick in the behind that I needed to get to an
alternative
> | solution. I can simply differentiate between the two cases by supplying
> | *two* template functions:
> |
> | template <typename T> void _report(T& _t);
> | template <typename T> void _report(const T& _t);
> |
> | Works for me :-)
>
> Actually the semantics of typeof haven't been worked out by the C++
> committee yet.  But what meeroh says is certainly true for our current
> implementation of it.

Yes, I learned the hard way as usual.
Interesting to observe the change in function signature as reported by
__PRETTY_FUNCTION__ after I added the second template function.

With only one function:
     template <typename T> void _report(T& _t)
        _report<long>(long &)
        _report<const long>(const long &)

With an additional function:
    template <typename T> void _report(const T& _t)
        _report<long>(long &)
        _report<long>(const long &)


It's the <long> and <const long> of the first case that got me going on thin
ice...
I must admit, I still don't get it exactly but I something that works!

>
> Glad you found a solution!
>
> If it helps any further, there is a neat little type traits (hinted at
> by meeroh) that lives in <msl_utility>.  You could have stuck it in
> your original _report like so:
>
>     if (Metrowerks::is_const<T>::value)
>       cout << "const\n";
>
> And it would have printed "const" for the const variants.

Thanks Howard. Had a look at that. God d... it, the things I don't know!
Time to throw everything away and start all over again...
Cheers,
Conrad Weyns.

>
> --
> Howard Hinnant
> Metrowerks