[boost] Re: Overload resolution & boost::bind

From: Jonathan Turkanis (technews_at_[hidden])
Date: 2004-08-17 15:45:26

<Arturo_Cuebas_at_[hidden]> wrote in message
news:OF6215D845.F05336EF-ON86256EF3.005F9390-86256EF3.00613932_at_bpmicro.com...
> The program below contains a compile error. Following the program
you
> will find the typical fix then my idea for a library that
facilitates
> a syntactically prettier fix.

<snip>

> struct C
> {
>     void F(char, char){}
>     void F(int, int){}
>     void F(char, int){}
>     void F(char){}
> };
>
> int main()
> {
>     C o;
>     bind(
>          C::F,   // error: which C::F?
>          &o, _1);
> }
>
> Typical solution:
>
> bind(static_cast<void (C::*)(char)>(C::F), &o, _1);

<snip>

> Here's my idea. If we had these:

<snip>

> ...etc; the bind call would look like this:
>
> bind(resolve_cast1<char>(C::F), &o, _1);

<snip>

> Is this worth the trouble?

I really like the idea. The main advantage is that you don't have to
repeat the class name, which may be long. E.g.

   void (symmetric_filter_adapter_impl::*close) () =
           &symmetric_filter_adapter_impl::close;

> Is it possible to implement a form without a number appended?

I can do it with this syntax:

    boost::resolve_cast<int()>(&C::g);
    boost::resolve_cast<int(int)>(&C::g);

using function types as in Boost.Function. Your version would be the
'portable syntax'.

> Is there a name better than resolve_cast?

Sounds okay to me.

> This was tested only in VC7.1.

You need to add &'s to former member function pointers. Otherwise it
looks okay to me. My version works on VC7.1, Como 4.3.3 and GCC 3.2.
I'll post it if there's interest.

Jonathan