[boost] [container][set, map, flat_set, flat_map, +multi_xxx] operator< and operator== seems to ignore custom KeyCompare

Hi Ion & others, I think that there might be a problem in the implementation of operator< for these containers. There might be a problem with operator== too. The problem is that they all use some variant of the following definition: template inline bool operator<(const rbtree& x, const rbtree& y) { return std::lexicographical_compare(x.begin(), x.end(), y.begin(), y.end()); } There is no KeyCompare (or other compare object) passsed to lexicographical compare. Reading up on the standard, it seems that all standard containers are implemented this way. Consequence: when having e.g. set, the comparison is not portable, since only std::less is guaranteed to be. So isn't this a defect? The other issue is perhaps more sensitive. What should users expect from typedef setstd::string,CaseInsensitiveLess Set; Set s1{ "foo", "BAR" }; Set s2{ "FOO", "bar" }; assert( s1 < s2 ); // true? assert( s1 == s2 ); // true? I was at least surprised by this behavior. regards Thorsten