I am getting an Access Violation using the array built-in sort.

My structure looks quite harmless:

class   EdgeInfo
{
  int     from, to;
  float   cost = 0;

  public int     opCmp( Object o )
  {
    EdgeInfo e = cast(EdgeInfo)o;
    float other = e.cost;
    if ( cost < other ) return -1;
    if ( equal( other , cost ) ) return 0; else return 1;
  }
}

if I use an external sort the problem doesnt occur.
If I change it to a class(and change the opCmp) it still happens.

Moving this to a test case file makes it vanish, and its a fairly lengthy routine (3d Mesh simplification).

The error occurs here:

Thread stopped.
MVIEW!_D6object8TypeInfo4swapFPvPvZv+0x1a

TypeInfo.swap() ??

stop occurs at 0x0041bf86 in the following:

_D6object8TypeInfo4swapFPvPvZv:
0x0041bf6c 50               push        eax
0x0041bf6d 8b08             mov         ecx,dword ptr [eax]
0x0041bf6f 53               push        ebx
0x0041bf70 31db             xor         ebx,ebx
0x0041bf72 55               push        ebp
0x0041bf73 56               push        esi
0x0041bf74 8b742414         mov         esi,dword ptr [esp+14]
0x0041bf78 57               push        edi
0x0041bf79 8b7c241c         mov         edi,dword ptr [esp+1c]
0x0041bf7d ff5124           call        dword ptr [ecx+24]
0x0041bf80 89c5             mov         ebp,eax
0x0041bf82 85c0             test        eax,eax
0x0041bf84 7411             je _D6object8TypeInfo4swapFPvPvZv+0000002b (0041bf97)
0x0041bf86 8a143b           mov         dl,byte ptr [edi+ebx]
0x0041bf89 8a0c33           mov         cl,byte ptr [esi+ebx]
0x0041bf8c 880c3b           mov         byte ptr [edi+ebx],cl
0x0041bf8f 881433           mov         byte ptr [esi+ebx],dl
0x0041bf92 43               inc         ebx
0x0041bf93 39eb             cmp         ebx,ebp
0x0041bf95 72ef             jb _D6object8TypeInfo4swapFPvPvZv+0000001a (0041bf86)
0x0041bf97 5f               pop         edi
0x0041bf98 5e               pop         esi
0x0041bf99 5d               pop         ebp
0x0041bf9a 5b               pop         ebx
0x0041bf9b 58               pop         eax
0x0041bf9c c20800           retn        0008
0x0041bf9f cc               int         3

Any tips would be helpful.
-DavidM

David Medlock wrote:
> I am getting an Access Violation using the array built-in sort.
> 
> My structure looks quite harmless:
> 
> class   EdgeInfo
> {
>   int     from, to;
>   float   cost = 0;
> 
>   public int     opCmp( Object o )
>   {
>     EdgeInfo e = cast(EdgeInfo)o;
>     float other = e.cost;
>     if ( cost < other ) return -1;
>     if ( equal( other , cost ) ) return 0; else return 1;
>   }
> }

Try checking that o is not null.

Walter Bright wrote:
> David Medlock wrote:
> 
>> I am getting an Access Violation using the array built-in sort.
>>
>> My structure looks quite harmless:
>>
>> class   EdgeInfo
>> {
>>   int     from, to;
>>   float   cost = 0;
>>
>>   public int     opCmp( Object o )
>>   {
>>     EdgeInfo e = cast(EdgeInfo)o;
>>     float other = e.cost;
>>     if ( cost < other ) return -1;
>>     if ( equal( other , cost ) ) return 0; else return 1;
>>   }
>> }
> 
> 
> Try checking that o is not null.
Well originally the EdgeInfo was an array of structs, each of which is appended on the array(so no nulls possible).  I tried EdgeInfo* and EdgeInfo, got the error either way.

Ended up taking the long way around the issue: I ported a public domain heapsort and insertion sort to D.

I can post these if anyone wants em.

-DavidM