Provide informative error for eltype(Union{})

laurentheirendt · Feb 11, 2017 · 7b332ac · 7b332ac
1 parent 379f18e
commit 7b332ac
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diff --git a/base/operators.jl b/base/operators.jl
@@ -861,6 +861,7 @@ Int8
 """
 eltype(::Type) = Any
 eltype(::Type{Any}) = Any
+eltype(::Type{Bottom}) = throw(ArgumentError("Union{} does not have elements"))
 eltype(t::DataType) = eltype(supertype(t))
 eltype(x) = eltype(typeof(x))
 

diff --git a/test/core.jl b/test/core.jl
@@ -4676,3 +4676,5 @@ if Sys.WORD_SIZE == 64
     end
     @test_nowarn tester20360()
 end
+
+@test_throws ArgumentError eltype(Bottom)
-Original file line number
+Diff line change
@@ Expand Up / @@ -4676,3 +4676,5 @@ if Sys.WORD_SIZE == 64 @@
         end
         @test_nowarn tester20360()
     end
+    @test_throws ArgumentError eltype(Bottom)