Merge pull request #687 from JuliaCollections/ox/misingheapconstructor

Fix BinaryMaxHeap type alias
JuliaCollections · Oct 3, 2020 · 353a340 · 353a340 · oxinabox · Oct 3, 2020
2 parents 355a7a8 + b316993
commit 353a340
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Showing 3 changed files with 14 additions and 2 deletions.
diff --git a/Project.toml b/Project.toml
@@ -1,6 +1,6 @@
 name = "DataStructures"
 uuid = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
-version = "0.18.6"
+version = "0.18.7"
 
 
 [deps]

diff --git a/src/heaps/binary_heap.jl b/src/heaps/binary_heap.jl
@@ -50,9 +50,15 @@ BinaryHeap(ordering::Base.Ordering, xs::AbstractVector{T}) where T = BinaryHeap{
 BinaryHeap{T, O}() where {T, O<:Base.Ordering} = BinaryHeap{T}(O())
 BinaryHeap{T, O}(xs::AbstractVector) where {T, O<:Base.Ordering} = BinaryHeap{T}(O(), xs)
 
+const DefaultReverseOrdering = Base.ReverseOrdering{Base.ForwardOrdering}
+
+# These constructors needed for BinaryMaxHeap, until we have https://github.com/JuliaLang/julia/pull/37822
+BinaryHeap{T, DefaultReverseOrdering}() where {T} = BinaryHeap{T}(Base.Reverse)
+BinaryHeap{T, DefaultReverseOrdering}(xs::AbstractVector) where {T} = BinaryHeap{T}(Base.Reverse, xs)
+
 # Forward/reverse ordering type aliases
 const BinaryMinHeap{T} = BinaryHeap{T, Base.ForwardOrdering}
-const BinaryMaxHeap{T} = BinaryHeap{T, Base.ReverseOrdering}
+const BinaryMaxHeap{T} = BinaryHeap{T, DefaultReverseOrdering}
 
 BinaryMinHeap(xs::AbstractVector{T}) where T = BinaryMinHeap{T}(xs)
 BinaryMaxHeap(xs::AbstractVector{T}) where T = BinaryMaxHeap{T}(xs)

diff --git a/test/test_binheap.jl b/test/test_binheap.jl
@@ -29,6 +29,12 @@
             @test true
         end
 
+        @testset "Type Aliases" begin
+            # https://github.com/JuliaCollections/DataStructures.jl/issues/686
+            @test BinaryMaxHeap{Int}() isa BinaryMaxHeap{Int}
+            @test BinaryMinHeap{Int}() isa BinaryMinHeap{Int}
+        end
+
         @testset "implicit conversion" begin
             BinaryHeap{Float64, Base.ForwardOrdering}(vs)
             BinaryMinHeap{Float64}(vs)