Merge pull request #869 from cmcaine/fix-mutable-binheap-unions

Fix MutableBinaryHeap{T} when T is Union/abstract

Author: oxinabox

src/heaps/mutable_binary_heap.jl

@@ -220,7 +220,7 @@ function Base.push!(h::MutableBinaryHeap{T}, v) where T
     nodemap = h.node_map
     i = length(nodemap) + 1
     nd_id = length(nodes) + 1
-    push!(nodes, MutableBinaryHeapNode(convert(T, v), i))
+    push!(nodes, MutableBinaryHeapNode{T}(convert(T, v), i))
     push!(nodemap, nd_id)
     _heap_bubble_up!(h.ordering, nodes, nodemap, nd_id)
     return i
@@ -266,7 +266,7 @@ function update!(h::MutableBinaryHeap{T}, i::Int, v) where T
     nd_id = nodemap[i]
     v0 = nodes[nd_id].value
     x = convert(T, v)
-    nodes[nd_id] = MutableBinaryHeapNode(x, i)
+    nodes[nd_id] = MutableBinaryHeapNode{T}(x, i)
     if Base.lt(ordering, x, v0)
         _heap_bubble_up!(ordering, nodes, nodemap, nd_id)
     else

test/test_mutable_binheap.jl

@@ -343,6 +343,16 @@ end
         @test isequal(heap_values(h), [0.5, 10.1, 3.0, 20.0])
     end
 
+    @testset "T is a Union" begin
+        h = MutableBinaryMinHeap{Union{Int, Float64}}()
+        push!(h, 1)
+        push!(h, 2.0)
+        update!(h, 1, 1.5)
+        update!(h, 2, 3)
+        @test pop!(h) === 1.5
+        @test pop!(h) === 3
+    end
+  
     @testset "empty!" begin
         vs = [4, 1, 3, 2, 16, 9, 10, 14, 8, 7]
         vs2 = collect(enumerate(vs))