Subject: Re: [boost] [afio] Formal review of Boost.AFIO
From: Thomas Heller (thom.heller_at_[hidden])
Date: 2015-08-31 10:57:04
On 08/31/2015 04:13 PM, Niall Douglas wrote:
> On 30 Aug 2015 at 22:47, Thomas Heller wrote:
>>> No, this stuff is at the core of where we are diverging in approach
>>> and why the AFIO API is so displeasing to you.
>>> Where I am coming from is this:
>>> "If the cost of defaulting to guaranteed memory safety to the end
>>> user is less than 0.5% overhead, I will default to guaranteed memory
>> Where did you get this number from?
> The benchmarks I ran before deciding on whether enforcing shared_ptr
> on handle was an acceptable overhead.
> You've got to understand Thomas you and your fellow HPC colleagues
> are attacking AFIO's "overhead" without having run any benchmarks.
> You're claiming all this poor performance and high overhead stuff
> having absolutely no idea of performance on the ground. As I much as
> I appreciate where you think you're coming from, the benchmarks I ran
> before deciding on a shared_ptr on every handle said it was an
> inconsequential overhead. That's why I chose that design.
Now now, I merely asked where you got the numbers from. Where I come from?
>From a purely API design, aka semantics point of view. You are the one
talking about high performance and stuff, but fail to deliver.
>> Why isn't it possible that consumers of AFIO implement all those ABI
>> stability stuff?
> You don't appear to understand well how ABI stable C++ is designed.
> It requires imposing costs on everybody. Look at the PIMPL idiom.
The PIMPL idiom has absolutely *nothing* to do with ABI stability.