on Tue Aug 23 2011, Ion Gaztañaga <igaztanaga-AT-gmail.com> wrote:
El 23/08/2011 17:17, Christopher Jefferson escribió:
When moving was originally discussed, things like 'destructive' and 'raw' moves were discussed, but it was decided in the end they were too dangerous, without proving substantial benefits. For example, you can rearrange a list of std::vectors with memcpy, but if you get half way through and an exception is thrown and you end up with the same vector left in two places in memory, horrible things will happen as they will refer to the same memory block.
IMHO, destructive move should be required always to be no-throw.
Destructive move is practically impossible to manage regardless of exceptions: void f() { SomeType x; if (some_condition) { something_that_moves(x) } else { x.foo() } // Do we call x's destructor? } Even if you say the compiler can solve the problem in that trivial case I can easily come up with slightly-less-trivial cases where the problem arises and is absolutely intractable. -- Dave Abrahams BoostPro Computing http://www.boostpro.com