Remove PhantomData<*mut Waiter>
so we don't need to manually impl Send
#237
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Outdated suggestions cannot be applied.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 effect of having
PhantomData<*mut Waiter>
is that theOnceCell<T>
stops beingimpl<T: Send> Send for OnceCell<T>
. But we want it to beimpl<T: Send> Send for OnceCell<T>
, because we manually mark it as such.By removing the
PhantomData
we can also remove the manualimpl Send
. The net effect is zero changes to the public API surface (including auto traits) ofonce_cell
:A variant of this PR is to remove the
PhantomData
but keep the manualimpl Send
. Maybe you prefer the explicitness.Background of this PR
I am studying how
once_cell
is implemented, and could not at first understand why we needed thePhantomData<*mut Waiter>
. Digging deeper, I concluded that we do not in fact need it.