unordered_*::erase(iterator) should not return an iterator

[anonymous]

please see

​http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2023.pdf

and this thread

​http://lists.boost.org/Archives/boost/2009/11/159116.php

in that thread it is mentioned that boost.intrusive doesn't have that problem, but that was referring to boost 1.38, in which erase(iterator) had a void result.

boost.unordered can't simply change the return type since its specified in TR1, but I think boost.intrusive should.

as far as I know there is good solution to this except a void return type. changing the data structure to enable O(1) erase again creates memory overhead. evaluating the returned iterator only on demand, e.g. on indirection, makes all iterator operations more expensive.

here`s boost.intrusive's implementation that causes the problem:

​http://lists.boost.org/Archives/boost/2009/11/159134.php

[anonymous]

"as far as I know there is good solution"

+not

[anonymous]

related to #3693

[anonymous]

there appears to be a consensus to change the result of std::unordered_*::erase to "void": ​http://home.roadrunner.com/~hinnant/issue_review/lwg-active.html#579

GCC changed it:

​http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41975

[Ion Gaztañaga]

Fixed for Boost 1.45 in release branch