improve inferrability of list_deletefirst! (JuliaLang#38236)

halleysfifthinc · Dec 1, 2020 · a69ecaa · a69ecaa
1 parent 8c35003
commit a69ecaa
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/base/linked_list.jl b/base/linked_list.jl
@@ -87,6 +87,7 @@ function popfirst!(q::InvasiveLinkedList{T}) where {T}
  return val
 end
 
+# this function assumes `val` is found in `q`
 function list_deletefirst!(q::InvasiveLinkedList{T}, val::T) where T
  val.queue === q || return
  head = q.head::T
@@ -97,10 +98,10 @@ function list_deletefirst!(q::InvasiveLinkedList{T}, val::T) where T
  q.head = val.next::T
  end
  else
- head_next = head.next
+ head_next = head.next::T
  while head_next !== val
  head = head_next
- head_next = head.next::Union{T, Nothing}
+ head_next = head.next::T
  end
  if q.tail::T === val
  head.next = nothing