scalar indexing broadcast fix (#442)

* scalar indexing broadcast fix

* add tests for scalar broadcast indexing

* add test for ref

Author: SimonDanisch

src/broadcast.jl

@@ -135,6 +135,10 @@ end
     end
 end
 
+scalar_getindex(x) = x
+scalar_getindex(x::Ref) = x[]
+scalar_getindex(x::Tuple{<: Any}) = x[1]
+
 @generated function _broadcast(f, ::Size{newsize}, s::Tuple{Vararg{Size}}, a...) where newsize
     first_staticarray = 0
     for i = 1:length(a)
@@ -150,7 +154,7 @@ end
     sizes = [sz.parameters[1] for sz ∈ s.parameters]
 
     while more
-        exprs_vals = [(!(a[i] <: AbstractArray) ? :(a[$i][]) : :(a[$i][$(broadcasted_index(sizes[i], current_ind))])) for i = 1:length(sizes)]
+        exprs_vals = [(!(a[i] <: AbstractArray) ? :(scalar_getindex(a[$i])) : :(a[$i][$(broadcasted_index(sizes[i], current_ind))])) for i = 1:length(sizes)]
         exprs[current_ind...] = :(f($(exprs_vals...)))
 
         # increment current_ind (maybe use CartesianIndices?)

test/broadcast.jl

@@ -1,3 +1,15 @@
+using StaticArrays, Base.Test
+struct ScalarTest end
+Base.:(+)(x::Number, y::ScalarTest) = x
+
+@testset "Scalar Broadcast" begin
+    for t in (SVector{2}, MVector{2}, SMatrix{2, 2}, MMatrix{2, 2})
+        x = rand(t)
+        @test x == @inferred(x .+ ScalarTest())
+        @test x .+ 1 == @inferred(x .+ Ref(1))
+    end
+end
+
 @testset "Broadcast sizes" begin
     @test @inferred(StaticArrays.broadcast_sizes(1, 1, 1)) === (Size(), Size(), Size())
     for t in (SVector{2}, MVector{2}, SMatrix{2, 2}, MMatrix{2, 2})