Remove algo code duplication

[Marc Glisse]

On Fri, 4 May 2012, Marc Glisse wrote:

> On Fri, 4 May 2012, François Dumont wrote:
>
>> I though that I wouldn't have to take care of this kind of use case but you 
>> are right I better handle it correctly.
>> 
>> So I am going to write tests challenging the number of constructors invoked 
>> when algos are used with or without my patch, in C++98 and C++11 modes.
>> 
>> To be continued...
>
> To be clear: I don't think it is possible to remove the operator< special 
> case and replace it with a forwarding functor (like you wrote, or like 
> Jonathan's) without some detectable difference. The only chance I can see 
> would be to somehow get the right &operator< (how do you ask the compiler to 
> perform overload resolution, but then not apply the function, just give you a 
> pointer?) and pass that bare function pointer to the algorithm.

Or instead of using directly a functor on the values, one could write the 
algorithm using a functor on iterators, which would take a and b and 
return either *a<*b or cmp(*a,*b). Maybe not so nice.

-- 
Marc Glisse