long compile time question

[thedeemon]

On Wednesday, 24 October 2012 at 03:50:47 UTC, Dan wrote:
> The following takes nearly three minutes to compile.
> The culprit is the line bar ~= B();
> What is wrong with this?
>
> Thanks,
> Dan
> ----------------
> struct B {
>   const size_t SIZE = 1024*64;
>   int[SIZE] x;
> }
>
> void main() {
>   B[] barr;
>   barr ~= B();
> }
> -----------------

The code DMD generates for initializing the struct does not use 
loops, so it's
xor     ecx, ecx
mov     [eax], ecx
mov     [eax+4], ecx
mov     [eax+8], ecx
mov     [eax+0Ch], ecx
mov     [eax+10h], ecx
mov     [eax+14h], ecx
mov     [eax+18h], ecx
mov     [eax+1Ch], ecx
mov     [eax+20h], ecx
mov     [eax+24h], ecx
mov     [eax+28h], ecx
mov     [eax+2Ch], ecx
mov     [eax+30h], ecx
mov     [eax+34h], ecx
mov     [eax+38h], ecx
...

So your code creates a lot of work for the compiler.