fix getindex of Fill with Trues (#149)

* fix getindex

hopefully addresses #148

* test

* refine

* restrict to OneTo

Author: JeffFessler

Project.toml

@@ -1,6 +1,6 @@
 name = "FillArrays"
 uuid = "1a297f60-69ca-5386-bcde-b61e274b549b"
-version = "0.11.7"
+version = "0.11.8"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/trues.jl

@@ -43,3 +43,11 @@ function Base.getindex(x::AbstractArray{T,N}, mask::Trues{N, NTuple{N,Base.OneTo
     end
     return x[trues(size(x))] # else revert to usual getindex method
 end
+
+# https://github.com/JuliaArrays/FillArrays.jl/issues/148
+function Base.getindex(
+    a::AbstractFill{T, 1, Tuple{Base.OneTo{Int}}},
+    b::Trues{1, Tuple{Base.OneTo{Int}}}) where T
+    @boundscheck length(a) == length(b) || throw(BoundsError(a, b))
+    return Fill(getindex_value(a), length(a))
+end

test/runtests.jl

@@ -1204,6 +1204,8 @@ end
     @test_throws BoundsError ones(3)[Trues(2)]
     @test_throws BoundsError setindex!(ones(3), zeros(3), Trues(2))
     @test_throws DimensionMismatch setindex!(ones(2), zeros(3), Trues(2))
+    @test Ones(3)[Trues(3)] == Ones(3)
+    @test_throws BoundsError Ones(3)[Trues(2)]
 end
 
 @testset "FillArray interface" begin