"Peter Dimov" <pdimov@mmltd.net> wrote in message news:003501c41363$d23fe7b0$1d00a8c0@pdimov2...
Jonathan Turkanis wrote:
This is probably the best characterization of the traits/policy distinction I've heard. I don't agree entirely about basic_string, however; I think that the comparison functions such as char_traits::compare have to be made available through template parameters, otherwise you wouldn't be able to reuse basic_string
if
you want strings with different comparison criteria.
I thought it was already common knowledge that the idea of using the 'char_traits' policy parameter of basic_string to override comparisons is inherently flawed. Usually the kind of comparison you want depends on the context where the string is used, not on the type of the string.
Yes, I know this argument, and in fact I have always used a comparison predicate when I need to customize string comparisons. 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; as long as it's provided, it should be customizable. Jonathan