On Wednesday, 25 November 2020 at 00:20:54 UTC, Paul Backus wrote:
The exact memory layout and ABI of SumType is deliberately left unspecified. It's an implementation detail that client code isn't supposed to rely on. If you want to pass a SumType's value to a C function, you will first have to extract it using pattern matching.
For me personally it would be more helpful if the layout/ABI was fully specified. I guess other people may have different opinions. In a systems language it is always more useful to have an exact specification of what the layout will be.
