Re: [boost] Reforming Boost.System and <system_error> round 2

Subject: Re: [boost] Reforming Boost.System and <system_error> round 2
From: Peter Dimov (lists_at_[hidden])
Date: 2018-01-16 13:54:26

Andrey Semashev wrote:

> In the generated code I noticed that the compiler generated a check of 
> whether the virtual function `failure` is actually
`experimental::error_category::failure`. If it is, the code uses an inlined 
version of this function (otherwise, the actual indirect call is performed). 
So if you comment `code_category_impl::failure` the test succeeds and the 
indirect call is avoided. Here are the results for this case:
>
> Experimental test: 71711 usec, 1394486201.559036 tests per second
> std test: 48177 usec, 2075679266.039812 tests per second
>
> This is still a 1.5x difference.

That's pretty good. In practice, if the function does something nontrivial, 
this amount of overhead will be entirely lost in the noise.