Remove algo code duplication

[Marc Glisse]

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.

However, just because it changes things a little bit doesn't mean using a 
forwarding functor shouldn't be done...

(by the way, as a core feature, it would be nice if default arguments 
could participate in template deduction, so we could write the algorithms 
with a single declaration, with the functor that defaults to our operator< 
wrapper)

-- 
Marc Glisse