[Boost-users] case insensitive less_than string comparison

16 Jul 2005

      Hi,

I am aware that string_algo has an if_iequal functor. Is there also an 
equivalent for a less-than comparison? I have to compare strings 
ignoring the case but taking locales into account.
Right now I'm calling boost::algorithm::to_lower on two copies of the 
original strings. I'm not so sure if this is very efficient when I'm 
comparing thousands of strings.

Here's the functor as it is now:

     struct FileLessNameA
         : std::binary_function {
         bool operator() (const File& lhs, const File& rhs) const {
             std::string path1( lhs.get_name().c_str() );
             std::string path2( rhs.get_name().c_str() );
             boost::algorithm::to_lower( path1 );
             boost::algorithm::to_lower( path2 );
             return path1 < path2;
         }
     };

Any suggestions for improvements appreciated :)

Regards,
Matthias

-- 
Matthias Kaeppler