Fix views with static boolean vector indexing (#1025)

* fix views with static boolean vector indexing

* type stability of views

* bump version

Author: mateuszbaran

Project.toml

@@ -1,6 +1,6 @@
 name = "StaticArrays"
 uuid = "90137ffa-7385-5640-81b9-e52037218182"
-version = "1.4.6"
+version = "1.4.7"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/MArray.jl

@@ -106,13 +106,21 @@ function promote_rule(::Type{<:MArray{S,T,N,L}}, ::Type{<:MArray{S,U,N,L}}) wher
     MArray{S,promote_type(T,U),N,L}
 end
 
+@generated function _indices_have_bools(indices::Tuple)
+    return any(index -> index <: StaticVector{<:Any,Bool}, indices.parameters)
+end
+
 function Base.view(
     a::MArray{S},
     indices::Union{Integer, Colon, StaticVector, Base.Slice, SOneTo}...,
 ) where {S}
-    new_size = new_out_size(S, indices...)
     view_from_invoke = invoke(view, Tuple{AbstractArray, typeof(indices).parameters...}, a, indices...)
-    return SizedArray{new_size}(view_from_invoke)
+    if _indices_have_bools(indices)
+        return view_from_invoke
+    else
+        new_size = new_out_size(S, indices...)
+        return SizedArray{new_size}(view_from_invoke)
+    end
 end
 
 Base.elsize(::Type{<:MArray{<:Any, T}}) where T = Base.elsize(Vector{T})

src/SizedArray.jl

@@ -193,8 +193,13 @@ function Base.view(
     a::SizedArray{S},
     indices::Union{Integer, Colon, StaticVector, Base.Slice, SOneTo}...,
 ) where {S}
-    new_size = new_out_size(S, indices...)
-    return SizedArray{new_size}(view(a.data, indices...))
+    view_of_wrapped = view(a.data, indices...)
+    if _indices_have_bools(indices)
+        return view_of_wrapped
+    else
+        new_size = new_out_size(S, indices...)
+        return SizedArray{new_size}(view_of_wrapped)
+    end
 end
 
 function Base.vec(a::SizedArray{S}) where {S}

test/MArray.jl

@@ -221,6 +221,12 @@
         @test v[] == 2
     end
 
+    @testset "boolean indexing" begin
+        v = @MArray [1,2,3]
+        b = view(v, SA[true, false, true])
+        @test b == [1,3]
+    end
+    
     @testset "non-power-of-2 element size" begin
         primitive type Test24 24 end
         Test24(n) = Base.trunc_int(Test24, n)

test/SizedArray.jl

@@ -225,6 +225,9 @@
         x6 = view(x, StaticArrays.SUnitRange(2, 3), :, 2)
         @test isa(x6, SizedArray{Tuple{2,3},Float64,2,2,<:SubArray{Float64,2}})
         @test x6 == view(x.data, StaticArrays.SUnitRange(2, 3), :, 2)
+
+        x7 = view(x, :, SA[true, false, true], 1)
+        @test x7 == view(x.data, :, SA[true, false, true], 1)
     end
 
     @testset "views of MArray" begin