I'm not sure if you could replicate System.String, because the oddity is happening at the metadata level - apart from special cases like String, .Net types must

I'm not sure if you could replicate System.String, because the oddity is happening at the metadata level - apart from special cases like String, .Net types must be compile-time constant length (if I remember correctly). However, at the instruction level you can do some pretty awesome stuff. This slice[1] library is able to verifiably and safely grab a slice of data out of any arbitrary structure by using a MSIL feature that was invented for C++/CLR. The call site[2] is not unsafe. [1]: https://github.com/joeduffy/slice.net/blob/master/src/PtrUtils.il https://github.com/joeduffy/slice.net/blob/master/src/PtrUti... [2]: https://github.com/joeduffy/slice.net/blob/master/src/Slice.cs#L56 https://github.com/joeduffy/slice.net/blob/master/src/Slice....