Remove invalid type assertion in CleverDicts

src/Utilities/CleverDicts.jl

@@ -257,8 +257,9 @@ Base.haskey(::CleverDict, key) = false
 # Here, we implement the iterate functions for our `CleverDict`. For either
 # backend (`OrderedDict` or `Vector`+`BitSet`) we return the same State type
 # so that `iterate` returns the same
-# type regardless of the backing datastructure. To help inference, we annotate
-# the return type.
+# type regardless of the backing datastructure. To help inference, we convert
+# the return type. Don't use a type-assertion because this doesn't support `V`
+# being an abstract type.
 
 struct State
     int::Int64
@@ -288,7 +289,7 @@ function Base.iterate(
             return nothing
         else
             el, i = itr
-            return el::Pair{K, V}, State(i)
+            return convert(Pair{K, V}, el), State(i)
         end
     end
 end
@@ -318,7 +319,7 @@ function Base.iterate(
             return nothing
         else
             el, i = itr
-            return el::Pair{K, V}, State(i)
+            return convert(Pair{K, V}, el), State(i)
         end
     end
 end

test/Utilities/CleverDicts.jl

@@ -16,6 +16,24 @@ CleverDicts.index_to_key(::Type{MyKey}, index::Int) = MyKey{index}()
         @test d[MyKey{1}()] == "first"
     end
 
+    @testset "Abstract Value" begin
+        d = CleverDicts.CleverDict{MathOptInterface.VariableIndex, Any}()
+        key = CleverDicts.add_item(d, :a)
+        @test key == MathOptInterface.VariableIndex(1)
+        @test d[MathOptInterface.VariableIndex(1)] == :a
+        key = CleverDicts.add_item(d, "b")
+        @test key == MathOptInterface.VariableIndex(2)
+        @test d[MathOptInterface.VariableIndex(2)] == "b"
+        for (k, v) in d
+            if k.value == 1
+                @test v == :a
+            else
+                @test k.value == 2
+                @test v == "b"
+            end
+        end
+    end
+
     @testset "get/set" begin
         d = CleverDicts.CleverDict{MathOptInterface.VariableIndex, String}()
         key = CleverDicts.add_item(d, "first")