Reinterpreting UInt64 as structure

Question

In my code I'm calculating an UInt64 value, then casting it like this:

return *(Cell*)packedUInt64;

Cell is a struct. Marshal.SizeOf(new Cell()) prints 8, so it should match an UInt64, but the cast above crashes with AccessViolationException. I could probably try safer methods such as Marshal.StructureToPtr, but I'm still wondering where's the error in my code? Maybe an alignment mismatch problem?

One reason I'm shying away from Marshal.StructureToPtr is that it's a bit slow. — Stefan Monov, Apr 02 '12 at 15:00
`StructureToPtr` is exactly what you need to use considering your even asking how to avoid using it. — Security Hound, Apr 02 '12 at 16:33

score 2 · Answer 1 · answered Apr 02 '12 at 15:03

If I understand you correctly, you're calculating a UInt64 value (how?) and then casting that to a POINTER. You're not actually converting it to a Cell struct, but to a memory location in which this Cell resides. The AccessViolationException, in that case, seems perfectly understandable.

Is this what you're actually trying to do, or did I misunderstand your code?

Reinterpreting UInt64 as structure

1 Answers1