On 05/06/2010 08:36 PM, OvermindDL1 wrote:
Greetings Boost Developers and Users,
It's my pleasure to announce that the review of Ion Gaztañagas' Move library starts May 10th and lasts until May 24th, 2010, unless an extension occurs.
I don't think, as implemented, is_movable works for non-class types (at least that used to be the case, and I think the only change in the implementation has been the introduction of a boost::mpl::bool_). I think for non-class types T, at least in c++03, is_movable<T> should evaluate to false without causing a compiler error. I don't recall seeing anything concerning has_nothrow_move other than a short description about how it defaults to false and could hurt performance if not specialized. Can you explain the intended use for has_nothrow_move? Is this related to N2983 [1]? Speaking of which, do you have any idea what the status of throwing move constructors is as far as the c++ committee is concerned, whether you agree with the resolution provided by N2983, and if so, have you thought about providing move_if_noexcept (or something similar)? If has_nothrow_move turns out to be widely used, it may be a good idea to package the "no-throw-ness" of the move constructor within a move emulation enabling macro (ENABLE_NOTHROW_MOVABLE), e.g., by defining a typedef that has_nothrow_move can detect, or maybe a boolean static constant within the class indicating whether the move constructor throws, so that you can make the "no-throw" property conditional on the "no-throw-ness" of member objects. In any case, one step at a time... As far as the utility of is_movable in c++0x, it looks like it's only used in uninitialized_move and uninitialized_copy_or_move. This doesn't seem like enough justification to provide it for c++0x, since uninitialized_{copy_or_}move *could* be implemented without it just fine. Furthermore, is_movable will only be true in c++0x if a movable type has a nested typedef boost_move_emulation_t, which seems to exclude, e.g., STL data structures. I would think a simpler course of action would be to relegate is_movable to strictly c++03... I've looked through the documentation and have typo suggestions, but I'll have to get to those later... - Jeff [1] https://svn.boost.org/svn/boost/sandbox/committee/rvalue_ref/N2983.html