On Fri, 7 Aug 2009 19:19:03 +0100
Jonathan Wakely <jwakely....@gmail.com> wrote:
2009/8/7 Maxim Dementiev:
It means that swap for user types could be defined either in std namespace
or in the user type namespace (argument-dependent name lookup).
Yes, this is intentional. swap() is a point of customisation point,
see http://www.ddj.com/cpp/184401876 and the definition in
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1691.html
Ok. Thanks!
On the other hand, distance (advance, etc.) for user types must be defined
in std namespace.
There is no need to customise std::distance(), or certainly a lot less
need, because the Standard Library can provide optimal implementations
for all possible iterator categories. The generic swap() function in
Dear Jonathan, what about structures like B-Trees where the speed is equal to random iterators on one node but is lesser when you
iterates though different nodes?
So, for me the question isn't "Do I really need it?"
But "Shall I extend the std namespace?"
Yours faithfully,
Max
