Compiler Error C2845

'operator' : pointer arithmetic not allowed on this type

You cannot increment the pointer to a managed class.

Managed Extensions for C++

You cannot increment the pointer to a __gc class. Also, string operators are only valid with /clr (not /clr:oldSyntax).

The following sample generates C2845:

// C2845b.cpp
// compile with: /clr:oldSyntax
using namespace System;
__gc class X {};

int main() {
   X *pX = new X;
   pX++;   // C2845

   String * a = new String("abc");
   String * b = new String("def");
   Console::WriteLine(a + b);   // C2845 not with /clr:oldSyntax
}