reduce_first on the value

Author: jishnub

src/fillalgebra.jl

@@ -354,7 +354,7 @@ end
 -(a::AbstractFill) = Fill(-getindex_value(a), size(a))
 
 # special-cased for type-stability, as Ones + Ones is not a Ones
-Base.reduce_first(::typeof(+), x::Ones) = convert(Fill, x)
+Base.reduce_first(::typeof(+), x::Ones) = Fill(Base.reduce_first(+, getindex_value(x)), axes(x))
 
 function +(a::Zeros{T}, b::Zeros{V}) where {T, V} # for disambiguity
     promote_shape(a,b)

test/runtests.jl

@@ -826,6 +826,7 @@ end
     @test_throws UndefKeywordError cumsum(Fill(1,1,5))
 
     @test @inferred(sum([Ones(4)])) ≡ Fill(1.0, 4)
+    @test @inferred(sum([Trues(4)])) ≡ Fill(1, 4)
 
     @testset "infinite arrays" begin
         r = InfiniteArrays.OneToInf()