Re: [boost] [Root Pointer] Benchmark

Subject: Re: [boost] [Root Pointer] Benchmark
From: Phil Bouchard (philippeb8_at_[hidden])
Date: 2016-03-15 20:55:02

On 03/15/2016 08:33 PM, Glen Fernandes wrote:
> On Tue, Mar 15, 2016 at 7:02 PM, Phil Bouchard wrote:
>> Ok I fixed it and the code will look like the following:
>>
>
> One more thing: I suspect the following will not work, with a glance
> at your code: Change 'U' into:
>
>      struct W {
>          explicit W(int) { }
>          W(const W&) = delete;
>          W(W&&) { }
>          W& operator=(const W&) = delete;
>          W& operator=(W&&) = delete;
>      };
>      struct U {
>          U(W&&) { }
>      };
>
> Now with shared_ptr and allocate_shared, this will compile just fine:
>
>      p1 = allocate_shared<U>(Allocator<U>(n1, m2), W(1));
>
> With root_ptr, I'm guessing you would change it to something like:
>
>      allocator_type a1(n1, m1);
>      p1 = new (a1) node(a1, W(1));
>
> Your implementation looks like it will try to copy W which would fail
> to compile.

It fails to compile (I do not support move semantics yet):

allocator.cpp:65:9: error: no matching function for call to ‘U::U(const W&)’
          ::new(p) U(std::forward<Args>(args)...);