Pinning 2D array of enum

Question

I have a specific issue passing enum from managed to unmanaged layer - basically with pinning the enum array.

My use case is I have a 1D array of reference type (T) which contains a buffer (2D array of enum backed by byte).

buffer (2D Array of enum backed by byte) is allocated on managed heap and I want to pass that buffer to unmanaged layer - to fill it with some values. At the same time I want to make sure that Garbage Collector (GC) does not move the buffer around when unmanaged method is filling in data to the buffer. In order to do that I have to pin the buffer. The language that I am using for managed code is C++/CLI, which provides 2 way of pinning the buffer

• cli::pin_ptr
• GCHandle

For some reason I cannot pin buffer using GCHandle - I get ArgumentException - may be because enum is non-blittable type.

I can pin buffer with cli::pin_ptr though, however problem with cli::pin_ptr is that because array of reference type in discussion, (which contains buffer - 2D array of enum backed by byte), can be variable length, I will need more than one pin_ptr (array of pin_ptr) to pin buffer in each reference type instance. And I cannot have array of cli::pin_ptr.

This is blocking me for implementing specific feature in .NET Application - as I cannot pin the 2D array of enum correctly.