Make broadcast treat all type arguments as scalars. (#19922)

Author: Sacha0

base/broadcast.jl

@@ -25,13 +25,13 @@ function broadcast!{T,S,N}(::typeof(identity), x::AbstractArray{T,N}, y::Abstrac
 end
 
 # logic for deciding the resulting container type
-containertype(x) = containertype(typeof(x))
-containertype(::Type) = Any
-containertype{T<:Ptr}(::Type{T}) = Any
-containertype{T<:Tuple}(::Type{T}) = Tuple
-containertype{T<:Ref}(::Type{T}) = Array
-containertype{T<:AbstractArray}(::Type{T}) = Array
-containertype{T<:Nullable}(::Type{T}) = Nullable
+_containertype(::Type) = Any
+_containertype{T<:Ptr}(::Type{T}) = Any
+_containertype{T<:Tuple}(::Type{T}) = Tuple
+_containertype{T<:Ref}(::Type{T}) = Array
+_containertype{T<:AbstractArray}(::Type{T}) = Array
+_containertype{T<:Nullable}(::Type{T}) = Nullable
+containertype(x) = _containertype(typeof(x))
 containertype(ct1, ct2) = promote_containertype(containertype(ct1), containertype(ct2))
 @inline containertype(ct1, ct2, cts...) = promote_containertype(containertype(ct1), containertype(ct2, cts...))
 

test/broadcast.jl

@@ -386,7 +386,7 @@ end
 Base.getindex(A::Array19745, i::Integer...) = A.data[i...]
 Base.size(A::Array19745) = size(A.data)
 
-Base.Broadcast.containertype{T<:Array19745}(::Type{T}) = Array19745
+Base.Broadcast._containertype{T<:Array19745}(::Type{T}) = Array19745
 
 Base.Broadcast.promote_containertype(::Type{Array19745}, ::Type{Array19745}) = Array19745
 Base.Broadcast.promote_containertype(::Type{Array19745}, ::Type{Array})      = Array19745
@@ -436,3 +436,11 @@ end
         @test f.([true, false]) == [true, "false"]
     end
 end
+
+# Test that broadcast treats type arguments as scalars, i.e. containertype yields Any,
+# even for subtypes of abstract array. (https://github.com/JuliaStats/DataArrays.jl/issues/229)
+let
+    @test Base.Broadcast.containertype(AbstractArray) == Any
+    @test broadcast(==, [1], AbstractArray) == BitArray([false])
+    @test broadcast(==, 1, AbstractArray) == false
+end