Slow performance compared to C++, ideas?

[deadalnix]

On Tuesday, 4 June 2013 at 12:29:10 UTC, John Colvin wrote:
> On Tuesday, 4 June 2013 at 05:22:39 UTC, Andrei Alexandrescu 
> wrote:
>> Situation: I have a closed source library I want to use. I 
>> test and find that it doesn't meet our requirements for some 
>> trivial matter like the behavior of a few methods (super 
>> common, I assure you).
>> The author is not responsive, possibly because it would be a 
>> potentially breaking change to all the other customers of the 
>> library, I've now wasted a month of production time in 
>> discussions in an already tight schedule, and I begin the 
>> process of re-inventing the wheel.
>> I've spent 10 years repeating this pattern. It will still be 
>> present with virtual-by-default, but it will be MUCH WORSE 
>> with final-by-default. I don't want to step backwards on this 
>> front.
>>
>> Destroyed?
>
> I don't buy this.
>
> Overriding a method from a class in a closed source library is 
> only a sane thing to do if the docs explicitly say you can.

For what it's worth, I did it a countless number of time in 
software that is in production right now.

> This virtual-by-default flexibility only exists when you're 
> working with classes that you understand the internals of.
>

No you understand its usage.

> Basically, final-by-default is safer and faster, 
> virtual-by-default is more convenient when working with open 
> source libraries.
>

Once again the fast claim fail to address or even consider other 
technique that can be used to finalize methods.