Reducing array.length triggers reallocation

[Ivan Kazmenko via Digitalmars-d-learn]

On Sunday, 27 December 2015 at 22:36:32 UTC, Ali Çehreli wrote:
> [Several hours later...]
>
> You know what... I bet there is no actual allocation at all. I 
> think what happens is, the code calls GC.realloc(24) and 
> realloc() does not do anything. However, it still reports to 
> the profiler that there was an allocation (attempt).
>
> Can someone verify that please. At least, can someone show 
> where GC.realloc() source is.
>
> Thank you,
> Ali

I believe it boils down to calling gc.gc.reallocNoSync in 
druntime: 
https://github.com/D-Programming-Language/druntime/blob/master/src/gc/gc.d#L603 .