Hi!
I'm not sure if and how it could be done, I've read many docs from
msdn and now i'm pretty pessimistic about it. Anyway, i have a
unmanaged C++ code that reads some files and loads an
System::Collection::ArrayList:
Here's unmanaged code that loads an ArrayList
[...]
while(dane->kol!=NULL)
{
    for(int i=0;i<dane->liczpol;i++)
    {
    char typ = (char)dane->tabtyp[i];
    if(typ=='1')
    {
          int* temp_int = (int*)dane->kol->buf;
     pole_kolejki->Add(__box(*temp_int));
        [...]
    else if(typ=='C'|| typ== 'c')
     {
      String* temp_str = new           String(dane->kol->buf);
      pole_kolejki->Add(temp_str);
     }
    }
    kolejka->Add(pole_kolejki);
    dane->kol=dane->kol->nast;
}
[...]

Then i have a function that returns an ArrayList (Kolejka_class is
class that provides the above functionality) :

__declspec(dllexport) /*Object __gc**/System::Collections::ArrayList*
__stdcall Kolejka_numery_kontrah(){

Kolejka_class* numery_kontrah_kol = new
Kolejka_class(&numery_kontrah);

return (static_cast<System::Collections::ArrayList*>(numery_kontrah_kol->pobierz_kolejke()));
}

Finally I have it in dll and want to call from managed C++ code:

public __value struct KolejkaDLL
{
  [DllImport("Kolejki.dll")]
  /*No idea how to marshal returning type */
  static public System::Collections::ArrayList*
Kolejka_numery_kontrah();
};
[...]
System::Collections::ArrayList*
KolejkiNET::Kolejka_wrapp::pobierz_Numery_Kontrah()
{
    lista=KolejkaDLL::Kolejka_numery_kontrah(); /*HERE I GET AN
EXCEPTION:
Can not marshal return value: The type definition of this type has no
layout information.*/
    return lista;   
}