Error msg for managed memory in passCopyToSink

[elcritch]

Adds an error message for this situation. It's possibly due to a compiler bug but it's easy to workaround in user code by adding a destructor once you know what's causing the issue.

What triggers this is a type that has a cursor in it. This error only shows up with Nim binaries built by Nimble which seem to have asserts enabled.

type WeakRef*[T] {.acyclic.} = object
  ## type alias descring a weak ref that *must* be cleaned up
  ## when it's actual object is set to be destroyed
  pt* {.cursor.}: T

I suspect the cursor bit combined with sink causes this error.

However, I can work around with this:

proc `=destroy`*[T](obj: WeakRef[T]) =
  discard

[Araq]

Why not fix the compiler instead to allow for this case?

[elcritch]

Why not fix the compiler instead to allow for this case?

I would but I don't really know my way around. Especially for something like cursor. Not sure where to begin. :)

[Araq]

Well isn't the solution here that "type contains ref" shall be false for "type contains a .cursor field with ref".

[elcritch]

Well isn't the solution here that "type contains ref" shall be false for "type contains a .cursor field with ref".

Hmmm, yeah I'll take a crack at it.