Daniel James wrote:
Peter Dimov wrote:
Daniel James wrote:
Oh dear, it's actually the header file that's out of date. I changed it because it won't work for custom character traits.
Why do you think so?
That's issue 6.17 from n1756. I think you can define char_traits to create a case-insensitive string, so you'd want to get the same hash values for "foo" as "FOO".
Do not give much weight to such char_traits definitions, issue 6.17 notwithstanding. The proposed extensions treat std::string as a container, not as... whatever the other aspect of std::string is supposed to be. That is, the hash value of a string s is defined as the hash value of the range s.begin(), s.end(). If you look at the container requirements table, you'll see that container equality is defined in terms of operator== on the elements. The (bold enough) author of a string that is not a container can provide an overload of hash_value (in the namespace of the corresponding traits class) with the appropriate semantics.