Given that the proposal specifically mentions using struct instead of class it isn't just C#'s handling that makes it difficult to leverage System.Tuple.
Funny, the BCL folks went with a class and we were assured it was a good decision. Maybe they just need to get their JIT up to date and do escape analysis so this kinda thing doesn't cost so much. (Easy for me to say they should do it...) After using Rust+LLVM I'm accustomed to the idea of not having to pay so much for features.
