Re: [boost] [filesystem] operator == performance

Subject: Re: [boost] [filesystem] operator == performance
From: Konstantin Litvinenko (to.darkangel_at_[hidden])
Date: 2009-01-19 15:46:16

Beman Dawes wrote:
> Good question.
> 
> While the other relationals have to use
> std::lexicographical_compare(), operators == and != can do a simple
> string compare, as you suggest.
> 
> SVN trunk updated. It is a bit too late for these changes to make it
> into 1.38.0, however.
> 

   Thanx!!!

> It would be interesting if you could report back what impact that
> change has on you timings.

    There is nothing unexpected to report :). Doing

typedef boost::filesystem::path location_t;

struct location_equal_to : std::binary_function<location_t, location_t, 
bool>
{
    bool operator()(const location_t& lhs, const location_t& rhs) const
    {
       return lhs.string() == rhs.string();
    }
};

to use location_equal_to predicate in unordered_map, I got no more 
do_increment and... remove this bottleneck at all. Can't say about 
numbers but this operator == replacement was very helpful.