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

From: John Torjo (john.lists_at_[hidden])
Date: 2004-08-19 01:41:47

Peter Dimov wrote:

> Jonathan Turkanis wrote:
> 
>> <Arturo_Cuebas_at_[hidden]> wrote in message
>> news:OF6215D845.F05336EF-ON86256EF3.005F9390-86256EF3.00613932_at_bpmicro.com... 
>>
>>
>> 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.
> 
> 
> template<class F, class X> F X::* resolve_cast( F X::* pm ) { return pm; }
> 
> looks like it ought to work. VC 7.1 doesn't like it, though. Neither 
> does GCC 3.2.3. The online Comeau compiles it.
> _______________________________________________

How about having two or three more functions: mem_fn1, mem_fn2, mem_fn3

When you want a certain overload, you specify those parameters that 
differenciate it from the other overloads, like:

class X {
1    void f(char);
2    int f(int);		
3    int f(int, int);
4    int f(int, long);
5    int f(int, int, int);
6    long f(int, char, long);
};

mem_fn1<void>(&X::f); // selects 1

mem_fn2<any_param,any_param,int>(&X::f); // selects 3
mem_fn3<long>(&X::f); // selects 6
mem_fn3<int>(&X::f); // selects 5

Best,
John

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