"Peter Dimov" <pdimov@mmltd.net> wrote in message news:004101c41369$2ca8cb90$1d00a8c0@pdimov2...
Jonathan Turkanis wrote:
However, if you accept that comparisons criteria are alway
contextual,
I think you must conclude that the comparison operators <, <=, etc. are completely useless. On the contrary, I like the ability to have a default comparison criteria that works a good deal of the time;
Agree.
as long as it's provided, it should be customizable.
Disagree. Your own logic doesn't support this conclusion: a default comparison works most of the time, therefore, it doesn't need to be customizable, because you could only customize it to _not work_ most of the time.
And for the string case, the downside to encoding a comparison in
Here's what I had in mind: for a particular application you might find that 'most of the time' you need a non-standard comparison criterion. It might make sense to let it be the default, so you can use the much cleaner operator notation. the type
is that you'll now spend a lot of time converting strings (because most libraries - correctly - accept an ordinary std::string, regardless of what comparisons they might make underneath, or they'd expose implementation details in the interface.)
You can expose the string as a typedef, to avoid bothering library users with custom comparison policies. Most of the interoperability concerns could be addressed by relaxing the requirement that traits_type match extacly in basic_string member functions which take basic_strings as arguments -- at least for those which don't involve comparison.
Nobody uses anything but std::string and std::wstring. ;-)
I've been waiting to meet the 'japan_char' I've read so much about; still haven't seen it. ;-) Jonathan