Re: [boost] [fiber] ready for next review

On 12/5/2015 12:05 PM, Oliver Kowalke wrote:

2015-12-05 15:03 GMT+01:00 Agustín K-ballo Bergé :

...

Furthermore, from a cursory look it seems C++11 allocators are not supported. The code assumes a C++03 allocator interface. If it is intentional then this requirement should be documented.

In class promise and packaged_task probably simply copy&paste the code from the StackAllocator snippets. What's wrong with allocator::allocate() + placement new instead of allocator::allocate() + allocator::construct()?

An allocator might do other stuff in `construct` besides placement-new construction, which is what the default `std::allocator_traits` does. An allocator might, for instance, choose to trace all calls and log them, or it might choose to defer construction to some other allocator. Allocators like `scoped_allocator_adaptor` inject additional arguments and/or select different constructors to call (although I do not think this applies here). An allocator might even reject to construct certain types or use certain types of arguments, which they do so by failing to instantiate `construct` (17.6.3.5 [allocator.requirements]/9). Furthermore, keep in mind that `allocator::allocate` does not necessarily return a **raw** pointer. Using `std::allocator_traits` here would, besides giving some support for C++11 allocators, also pick the right placement-new to call in the case of nasty overloads (current code correctly qualifies `::new` but fails to secure a `void*` argument). Also, use of the replaceable standard library placement new requires `#include <new>`. Regards, -- Agustín K-ballo Bergé.- http://talesofcpp.fusionfenix.com