fix #28915, identity conversion to union of tuple types #28951
Merged
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The problem here was that a definition for converting to
Type{T} where T<:Tuple
intercepts unions of tuple types, which might not supportfieldtype
. This is the simplest fix I could come up with. So far I haven't found a way to do it with fewer than 6 definitions (2 for each of 3 "kinds" of tuple types). Alternatively, we could makefieldtype(Union{Tuple{}, Tuple{Int}}, 1)
returnInt
instead of throwing an error. That would be a more invasive change though, so I left it for later.