Type-stability in subblocks (#232)

* type-stability in subblocks

* Add 1D test

* fix test on v1.6

* version bump to v0.16.22

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "BlockArrays"
 uuid = "8e7c35d0-a365-5155-bbbb-fb81a777f24e"
-version = "0.16.21"
+version = "0.16.22"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"

src/blockbroadcast.jl

@@ -135,9 +135,6 @@ subblocks(::Any, bs::NTuple{N,AbstractUnitRange{Int}}, dim::Integer) where N =
     (nothing for _ in blockaxes(bs[dim], 1))
 
 function subblocks(arr::AbstractArray, bs::NTuple{N,AbstractUnitRange{Int}}, dim::Integer) where N
-    if size(arr, dim) == 1
-        return (BlockIndexRange(Block(1), 1:1) for _ in blockaxes(bs[dim], 1))
-    end
     return SubBlockIterator(arr, bs, dim)
 end
 

test/test_blockbroadcast.jl

@@ -251,4 +251,18 @@ import BlockArrays: SubBlockIterator, BlockIndexRange, Diagonal
 
         @test [idx.indices[1] for idx in SubBlockIterator(subblock_lasts, block_lasts)] == [1:1,1:2,1:1,2:3]
     end
+
+    @testset "Adding BlockArrays" begin
+        B = mortar(reshape([ones(1,1)], 1, 1))
+        C = B + B
+        @test C[Block(1,1)] == 2B[Block(1,1)]
+
+        B = mortar(reshape([[1 2], [3 4]], 1, 2))
+        C = B + B
+        @test C[Block(1,1)] == 2B[Block(1,1)]
+
+        B = mortar(reshape([[1]], 1))
+        C = B + B
+        @test C[Block(1)] == 2B[Block(1)]
+    end
 end