Remove algo duplication

[Paolo Carlini]

Hi,

On 09/17/2013 12:27 PM, Marc Glisse wrote:
> I am quite convinced there is no significant backward compatibility 
> issue, less<void> was simply meaningless beforehand, that's why it was 
> so easy to have the new less<void> accepted in the standard. Adding it 
> in C++11 (not just C++14) is basically free. Whether we want a C++03 
> emulation is a harder question.
For the time being, would you be willing to prepare an actual patch for 
C++11? I think we should also have a couple of tests, besides the code 
you already posted.

Thanks,
Paolo.